diff --git a/src/gui/CMakeLists.txt b/src/gui/CMakeLists.txt
index 024bcfab426..db7c0590611 100644
--- a/src/gui/CMakeLists.txt
+++ b/src/gui/CMakeLists.txt
@@ -1059,6 +1059,11 @@ qt_internal_extend_target(Gui CONDITION UNIX AND (QT_FEATURE_xcb OR NOT MACOS) A
         platform/unix/qgnometheme_p.h platform/unix/qgnometheme.cpp
 )
 
+qt_internal_extend_target(Gui CONDITION UNIX AND QT_FEATURE_dbus AND (QT_FEATURE_xcb OR QT_FEATURE_wayland)
+    SOURCES
+        platform/unix/qgnomeportalinterface.cpp platform/unix/qgnomeportalinterface_p.h
+)
+
 qt_internal_extend_target(Gui CONDITION TARGET Qt::DBus AND UNIX AND (QT_FEATURE_xcb OR NOT MACOS) AND (QT_FEATURE_xcb OR NOT UIKIT)
     SOURCES
         platform/unix/dbusmenu/qdbusmenuadaptor.cpp platform/unix/dbusmenu/qdbusmenuadaptor_p.h
@@ -1068,6 +1073,7 @@ qt_internal_extend_target(Gui CONDITION TARGET Qt::DBus AND UNIX AND (QT_FEATURE
         platform/unix/dbusmenu/qdbusmenutypes.cpp platform/unix/dbusmenu/qdbusmenutypes_p.h
         platform/unix/dbusmenu/qdbusplatformmenu.cpp platform/unix/dbusmenu/qdbusplatformmenu_p.h
         platform/unix/qdbuslistener_p.h platform/unix/qdbuslistener.cpp
+        platform/unix/qdbussettings_p.h platform/unix/qdbussettings.cpp
 )
 
 qt_internal_extend_target(Gui CONDITION QT_FEATURE_systemtrayicon AND TARGET Qt::DBus AND UNIX AND (QT_FEATURE_xcb OR NOT MACOS) AND (QT_FEATURE_xcb OR NOT UIKIT)
diff --git a/src/gui/platform/unix/qdbuslistener.cpp b/src/gui/platform/unix/qdbuslistener.cpp
index 374b3a0f8ec..5057931b12d 100644
--- a/src/gui/platform/unix/qdbuslistener.cpp
+++ b/src/gui/platform/unix/qdbuslistener.cpp
@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
 #include "qdbuslistener_p.h"
+#include "qdbussettings_p.h"
 #include <private/qguiapplication_p.h>
 #include <qpa/qplatformintegration.h>
 #include <qpa/qplatformservices.h>
@@ -48,38 +49,6 @@ constexpr auto setting() { return "Setting"_L1; }
 constexpr auto dbusSignals() { return "DbusSignals"_L1; }
 constexpr auto root() { return "Q_L1.qpa.DBusSignals"_L1; }
 } // namespace JsonKeys
-
-namespace XdgSettings {
-// XDG Desktop Portal Settings (Preferred)
-// https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.freedesktop.portal.Settings.html
-constexpr auto contrastNamespace = "org.freedesktop.appearance"_L1;
-constexpr auto contrastKey = "contrast"_L1;
-// XDG portal provides the contrast preference value as uint:
-// 0 for no-preference, and, 1 for high-contrast.
-Qt::ContrastPreference convertContrastPreference(const QVariant &value)
-{
-    if (!value.isValid())
-        return Qt::ContrastPreference::NoPreference;
-    return static_cast<Qt::ContrastPreference>(value.toUInt());
-}
-} // namespace XdgSettings
-
-namespace GSettings {
-// GNOME Destop Settings (Alternative)
-// https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2069
-// https://gitlab.gnome.org/GNOME/gsettings-desktop-schemas/-/commit/0e97f1f571c495184f80d875c68f241261a50e30
-constexpr auto contrastNamespace = "org.gnome.desktop.a11y.interface"_L1;
-constexpr auto contrastKey = "high-contrast"_L1;
-// GSetting provides the contrast value as boolean:
-// true for enabled high-contrast, and, false for disabled high-contrast.
-Qt::ContrastPreference convertContrastPreference(const QVariant &value)
-{
-    if (!value.isValid())
-        return Qt::ContrastPreference::NoPreference;
-    return value.toBool() ? Qt::ContrastPreference::HighContrast
-                          : Qt::ContrastPreference::NoPreference;
-}
-} // namespace GSettings
 } // namespace
 
 void QDBusListener::init(const QString &service, const QString &path,
@@ -237,14 +206,15 @@ void QDBusListener::populateSignalMap()
     m_signalMap.insert(DBusKey("org.gnome.desktop.interface"_L1, "gtk-theme"_L1),
                        ChangeSignal(Provider::Gtk, Setting::Theme));
 
-    m_signalMap.insert(DBusKey("org.freedesktop.appearance"_L1, "color-scheme"_L1),
+    using namespace QDBusSettings;
+    m_signalMap.insert(DBusKey(XdgSettings::AppearanceNamespace, XdgSettings::ColorSchemeKey),
                        ChangeSignal(Provider::Gnome, Setting::ColorScheme));
 
-    m_signalMap.insert(DBusKey(XdgSettings::contrastNamespace, XdgSettings::contrastKey),
+    m_signalMap.insert(DBusKey(XdgSettings::AppearanceNamespace, XdgSettings::ContrastKey),
                        ChangeSignal(Provider::Gnome, Setting::Contrast));
     // Alternative solution if XDG desktop portal setting is not accessible,
     // e.g. when using the XDG portal version 1.
-    m_signalMap.insert(DBusKey(GSettings::contrastNamespace, GSettings::contrastKey),
+    m_signalMap.insert(DBusKey(GnomeSettings::AllyNamespace, GnomeSettings::ContrastKey),
                        ChangeSignal(Provider::Gnome, Setting::Contrast));
 
     const QString &saveJsonFile = qEnvironmentVariable("QT_QPA_DBUS_SIGNALS_SAVE");
@@ -274,13 +244,17 @@ void QDBusListener::onSettingChanged(const QString &location, const QString &key
     QVariant settingValue = value.variant();
 
     switch (setting) {
+    case Setting::ColorScheme:
+        settingValue.setValue(QDBusSettings::XdgSettings::convertColorScheme(settingValue));
+        break;
     case Setting::Contrast:
+        using namespace QDBusSettings;
         // To unify the value, it's necessary to convert the DBus value to Qt::ContrastPreference.
         // Then the users of the value don't need to parse the raw value.
-        if (key == XdgSettings::contrastKey)
+        if (key == XdgSettings::ContrastKey)
             settingValue.setValue(XdgSettings::convertContrastPreference(settingValue));
-        else if (key == GSettings::contrastKey)
-            settingValue.setValue(GSettings::convertContrastPreference(settingValue));
+        else if (key == GnomeSettings::ContrastKey)
+            settingValue.setValue(GnomeSettings::convertContrastPreference(settingValue));
         else
             Q_UNREACHABLE_IMPL();
         break;
diff --git a/src/gui/platform/unix/qdbussettings.cpp b/src/gui/platform/unix/qdbussettings.cpp
new file mode 100644
index 00000000000..8d5f5d972bc
--- /dev/null
+++ b/src/gui/platform/unix/qdbussettings.cpp
@@ -0,0 +1,47 @@
+// Copyright (C) 2025 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#include "qdbussettings_p.h"
+#include <QtCore/qvariant.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace QDBusSettings::XdgSettings {
+// https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.freedesktop.portal.Settings.html
+enum class ColorScheme : uint { NoPreference, PreferDark, PreferLight };
+} // namespace QDBusSettings::XdgSettings
+
+Qt::ContrastPreference QDBusSettings::XdgSettings::convertContrastPreference(const QVariant &value)
+{
+    // XDG portal provides the contrast preference value as uint:
+    // 0 for no-preference, and, 1 for high-contrast.
+    if (!value.isValid())
+        return Qt::ContrastPreference::NoPreference;
+    return static_cast<Qt::ContrastPreference>(value.toUInt());
+}
+
+Qt::ColorScheme QDBusSettings::XdgSettings::convertColorScheme(const QVariant &value)
+{
+    switch (ColorScheme{ value.toUInt() }) {
+    case ColorScheme::NoPreference:
+        return Qt::ColorScheme::Unknown;
+    case ColorScheme::PreferDark:
+        return Qt::ColorScheme::Dark;
+    case ColorScheme::PreferLight:
+        return Qt::ColorScheme::Light;
+    }
+    Q_UNREACHABLE_RETURN(Qt::ColorScheme::Unknown);
+}
+
+Qt::ContrastPreference
+QDBusSettings::GnomeSettings::convertContrastPreference(const QVariant &value)
+{
+    // GSetting provides the contrast value as boolean:
+    // true for enabled high-contrast, and, false for disabled high-contrast.
+    if (!value.isValid())
+        return Qt::ContrastPreference::NoPreference;
+    return value.toBool() ? Qt::ContrastPreference::HighContrast
+                          : Qt::ContrastPreference::NoPreference;
+}
+
+QT_END_NAMESPACE
diff --git a/src/gui/platform/unix/qdbussettings_p.h b/src/gui/platform/unix/qdbussettings_p.h
new file mode 100644
index 00000000000..7d7ea476464
--- /dev/null
+++ b/src/gui/platform/unix/qdbussettings_p.h
@@ -0,0 +1,46 @@
+// Copyright (C) 2025 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#ifndef QDBUSSETTINGS_P_H
+#define QDBUSSETTINGS_P_H
+
+#include <QtCore/qnamespace.h>
+#include <QtCore/qstring.h>
+QT_REQUIRE_CONFIG(dbus);
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API. It exists purely as an
+// implementation detail. This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+QT_BEGIN_NAMESPACE
+
+namespace QDBusSettings {
+// XDG Desktop Portal Settings (Preferred)
+// https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.freedesktop.portal.Settings.html
+namespace XdgSettings {
+static constexpr QLatin1StringView AppearanceNamespace{ "org.freedesktop.appearance" };
+static constexpr QLatin1StringView ColorSchemeKey{ "color-scheme" };
+static constexpr QLatin1StringView ContrastKey{ "contrast" };
+Qt::ContrastPreference convertContrastPreference(const QVariant &value);
+Qt::ColorScheme convertColorScheme(const QVariant &value);
+} // namespace XdgSettings
+
+namespace GnomeSettings {
+// GNOME Destop Settings (Alternative)
+// https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2069
+// https://gitlab.gnome.org/GNOME/gsettings-desktop-schemas/-/commit/0e97f1f571c495184f80d875c68f241261a50e30
+static constexpr QLatin1StringView AllyNamespace{ "org.gnome.desktop.a11y.interface" };
+static constexpr QLatin1StringView ContrastKey{ "high-contrast" };
+Qt::ContrastPreference convertContrastPreference(const QVariant &value);
+} // namespace GnomeSettings
+} // namespace QDBusSettings
+
+QT_END_NAMESPACE
+#endif // QDBUSSETTINGS_P_H
diff --git a/src/gui/platform/unix/qgnomeportalinterface.cpp b/src/gui/platform/unix/qgnomeportalinterface.cpp
new file mode 100644
index 00000000000..8528ed19328
--- /dev/null
+++ b/src/gui/platform/unix/qgnomeportalinterface.cpp
@@ -0,0 +1,175 @@
+// Copyright (C) 2025 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#include "qgnomeportalinterface_p.h"
+#include "qdbussettings_p.h"
+#include <private/qdbusplatformmenu_p.h>
+#include <QtDBus/QDBusMessage>
+#include <QtDBus/QDBusPendingCall>
+#include <QtDBus/QDBusReply>
+#include <QtDBus/QDBusVariant>
+
+QT_BEGIN_NAMESPACE
+
+#if QT_CONFIG(dbus)
+Q_STATIC_LOGGING_CATEGORY(lcQpaThemeGnome, "qt.qpa.theme.gnome")
+#endif // QT_CONFIG(dbus)
+
+using namespace Qt::StringLiterals;
+
+QGnomePortalInterface::QGnomePortalInterface(QObject *parent)
+    : QObject(parent), m_dbus{ new QDBusListener }
+{
+    QObject::connect(m_dbus.get(), &QDBusListener::settingChanged, this,
+                     &QGnomePortalInterface::dbusSettingChanged);
+
+    querySettings();
+}
+
+/*!
+    \internal
+    \brief QGnomePortalInterface::colorScheme
+    This is a getter method for the color-scheme loaded from the DBus portal.
+    \param fallback indicates the fallback color-scheme.
+    \return returns the cached color-scheme. If the color-scheme was not loaded
+    it returns the \a fallback color-scheme.
+ */
+Qt::ColorScheme QGnomePortalInterface::colorScheme(Qt::ColorScheme fallback) const
+{
+    if (!m_colorScheme.has_value())
+        return fallback;
+    return m_colorScheme.value();
+}
+
+/*!
+    \internal
+    \brief QGnomePortalInterface::contrastPreference
+    This is a getter method for the contrast-preference loaded from the DBus portal.
+    \param fallback indicates the fallback contrast-preference.
+    \return returns the cached contrast-preference if it was loaded. Otherwise,
+    returns the \a fallback contrast-preference.
+ */
+Qt::ContrastPreference
+QGnomePortalInterface::contrastPreference(Qt::ContrastPreference fallback) const
+{
+    if (!m_contrast.has_value())
+        return fallback;
+    return m_contrast.value();
+}
+
+void QGnomePortalInterface::querySettings()
+{
+    QDBusConnection dbus = QDBusConnection::sessionBus();
+    if (!dbus.isConnected()) {
+        qCWarning(lcQpaThemeGnome) << "dbus connection failed. Last error: " << dbus.lastError();
+        return;
+    }
+
+    constexpr auto method = "ReadAll"_L1;
+    auto message = QDBusMessage::createMethodCall(s_service, s_path, s_interface, method);
+
+    message << QStringList{ QDBusSettings::XdgSettings::AppearanceNamespace,
+                            QDBusSettings::GnomeSettings::AllyNamespace };
+
+    QDBusPendingCall pendingCall = dbus.asyncCall(message);
+    QDBusPendingCallWatcher *watcher = new QDBusPendingCallWatcher(pendingCall, this);
+
+    auto onWatcherFinished = [&](QDBusPendingCallWatcher *watcher) {
+        const QDBusMessage reply = watcher->reply();
+        if (QDBusMessage::ErrorMessage == reply.type()) {
+            qCWarning(lcQpaThemeGnome)
+                    << "dbus reply error: [" << reply.errorName() << "]" << reply.errorMessage();
+            watcher->deleteLater();
+            return;
+        }
+
+        const auto convertXdgColorScheme = [](const QVariant &value) {
+            using namespace QDBusSettings::XdgSettings;
+            return QVariant::fromValue(convertColorScheme(value));
+        };
+
+        constexpr auto XdgContrastKey = QDBusSettings::XdgSettings::ContrastKey;
+        const auto convertXdgContrast = [](const QVariant &value) {
+            using namespace QDBusSettings::XdgSettings;
+            return QVariant::fromValue(convertContrastPreference(value));
+        };
+
+        constexpr auto GnomeContrastKey = QDBusSettings::GnomeSettings::ContrastKey;
+        const auto convrtGnomeContrast = [](const QVariant &value) {
+            using namespace QDBusSettings::GnomeSettings;
+            return QVariant::fromValue(convertContrastPreference(value));
+        };
+
+        const QVariantList &args = reply.arguments();
+        for (const QVariant &arg_ : args) {
+            const QMap<QString, QVariantMap> arg = qdbus_cast<QMap<QString, QVariantMap>>(arg_);
+            for (auto aIt = arg.begin(); aIt != arg.end(); ++aIt) {
+                const QString &namespace_ = aIt.key();
+                const QVariantMap &settings = aIt.value();
+                for (auto sIt = settings.begin(); sIt != settings.end(); ++sIt) {
+                    const QString &key = sIt.key();
+                    const QVariant &value = sIt.value();
+                    if ((key == QDBusSettings::XdgSettings::ColorSchemeKey)
+                        && (namespace_ == QDBusSettings::XdgSettings::AppearanceNamespace))
+                        dbusSettingChanged(QDBusListener::Provider::Gnome,
+                                           QDBusListener::Setting::ColorScheme,
+                                           convertXdgColorScheme(value));
+                    else if ((key == XdgContrastKey)
+                             && (namespace_ == QDBusSettings::XdgSettings::AppearanceNamespace))
+                        dbusSettingChanged(QDBusListener::Provider::Gnome,
+                                           QDBusListener::Setting::Contrast,
+                                           convertXdgContrast(value));
+                    else if ((key == GnomeContrastKey)
+                             && (namespace_ == QDBusSettings::GnomeSettings::AllyNamespace))
+                        dbusSettingChanged(QDBusListener::Provider::Gnome,
+                                           QDBusListener::Setting::Contrast,
+                                           convrtGnomeContrast(value));
+                }
+            }
+        }
+        watcher->deleteLater();
+    };
+    connect(watcher, &QDBusPendingCallWatcher::finished, this, onWatcherFinished);
+}
+
+void QGnomePortalInterface::updateColorScheme(Qt::ColorScheme colorScheme)
+{
+    if (m_colorScheme.has_value() && (m_colorScheme.value() == colorScheme))
+        return;
+    m_colorScheme = colorScheme;
+    emit colorSchemeChanged(colorScheme);
+}
+
+void QGnomePortalInterface::updateContrast(Qt::ContrastPreference contrast)
+{
+    if (m_contrast.has_value() && (m_contrast.value() == contrast))
+        return;
+    m_contrast = contrast;
+    emit contrastChanged(contrast);
+}
+
+void QGnomePortalInterface::dbusSettingChanged(QDBusListener::Provider provider,
+                                               QDBusListener::Setting setting,
+                                               const QVariant &value)
+{
+    if (provider != QDBusListener::Provider::Gnome && provider != QDBusListener::Provider::Gtk)
+        return;
+
+    switch (setting) {
+    case QDBusListener::Setting::ColorScheme:
+        updateColorScheme(value.value<Qt::ColorScheme>());
+        break;
+    case QDBusListener::Setting::Contrast:
+        updateContrast(value.value<Qt::ContrastPreference>());
+        break;
+    case QDBusListener::Setting::Theme:
+        emit themeNameChanged(value.toString());
+        break;
+    default:
+        break;
+    }
+}
+
+QT_END_NAMESPACE
+
+#include "moc_qgnomeportalinterface_p.cpp"
diff --git a/src/gui/platform/unix/qgnomeportalinterface_p.h b/src/gui/platform/unix/qgnomeportalinterface_p.h
new file mode 100644
index 00000000000..4dee4f310f5
--- /dev/null
+++ b/src/gui/platform/unix/qgnomeportalinterface_p.h
@@ -0,0 +1,63 @@
+// Copyright (C) 2025 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#ifndef QGNOMEPORTALINTERFACE_P_H
+#define QGNOMEPORTALINTERFACE_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtCore/qtconfigmacros.h>
+QT_REQUIRE_CONFIG(dbus);
+
+#include <QtCore/QObject>
+#include <QtGui/private/qdbuslistener_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class Q_GUI_EXPORT QGnomePortalInterface : public QObject
+{
+    Q_OBJECT
+
+public:
+    QGnomePortalInterface(QObject *parent = nullptr);
+    ~QGnomePortalInterface() = default;
+
+    Qt::ColorScheme colorScheme(Qt::ColorScheme fallback = Qt::ColorScheme::Unknown) const;
+    Qt::ContrastPreference contrastPreference(
+            Qt::ContrastPreference fallback = Qt::ContrastPreference::NoPreference) const;
+
+private:
+    void querySettings();
+    void updateColorScheme(Qt::ColorScheme colorScheme);
+    void updateContrast(Qt::ContrastPreference contrast);
+
+Q_SIGNALS:
+    void colorSchemeChanged(Qt::ColorScheme);
+    void contrastChanged(Qt::ContrastPreference);
+    void themeNameChanged(const QString &themeName);
+
+private Q_SLOTS:
+    void dbusSettingChanged(QDBusListener::Provider, QDBusListener::Setting, const QVariant &value);
+
+private:
+    mutable uint m_version = 0; // cached version value
+    std::optional<Qt::ColorScheme> m_colorScheme;
+    std::optional<Qt::ContrastPreference> m_contrast;
+    std::unique_ptr<QDBusListener> m_dbus;
+    static constexpr QLatin1StringView s_service{ "org.freedesktop.portal.Desktop" };
+    static constexpr QLatin1StringView s_path{ "/org/freedesktop/portal/desktop" };
+    static constexpr QLatin1StringView s_interface{ "org.freedesktop.portal.Settings" };
+};
+
+QT_END_NAMESPACE
+
+#endif // QGNOMEPORTALINTERFACE_P_H
diff --git a/src/gui/platform/unix/qgnometheme.cpp b/src/gui/platform/unix/qgnometheme.cpp
index 389ea0238aa..a9fb85e15bc 100644
--- a/src/gui/platform/unix/qgnometheme.cpp
+++ b/src/gui/platform/unix/qgnometheme.cpp
@@ -5,163 +5,13 @@
 #include <qpa/qplatformdialoghelper.h>
 #include <qpa/qplatformfontdatabase.h>
 #if QT_CONFIG(dbus)
-#include "qdbuslistener_p.h"
-#include <private/qdbustrayicon_p.h>
-#include <private/qdbustrayicon_p.h>
-#include <private/qdbusplatformmenu_p.h>
-#include <private/qdbusmenubar_p.h>
-#include <QtDBus/QDBusMessage>
-#include <QtDBus/QDBusPendingCall>
-#include <QtDBus/QDBusReply>
-#include <QtDBus/QDBusVariant>
+#  include <private/qdbustrayicon_p.h>
+#  include <private/qdbusmenubar_p.h>
 #endif
 #include <qpa/qwindowsysteminterface.h>
 
 QT_BEGIN_NAMESPACE
 
-#if QT_CONFIG(dbus)
-Q_STATIC_LOGGING_CATEGORY(lcQpaThemeGnome, "qt.qpa.theme.gnome")
-
-using namespace Qt::StringLiterals;
-
-namespace {
-// https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.freedesktop.portal.Settings.html
-enum class XDG_ColorScheme : uint { NoPreference, PreferDark, PreferLight };
-
-constexpr Qt::ColorScheme convertColorScheme(XDG_ColorScheme colorScheme)
-{
-    switch (colorScheme) {
-    case XDG_ColorScheme::NoPreference:
-        return Qt::ColorScheme::Unknown;
-    case XDG_ColorScheme::PreferDark:
-        return Qt::ColorScheme::Dark;
-    case XDG_ColorScheme::PreferLight:
-        return Qt::ColorScheme::Light;
-    default:
-        Q_UNREACHABLE_RETURN(Qt::ColorScheme::Unknown);
-        break;
-    }
-}
-
-constexpr XDG_ColorScheme convertColorScheme(Qt::ColorScheme colorScheme)
-{
-    switch (colorScheme) {
-    case Qt::ColorScheme::Unknown:
-        return XDG_ColorScheme::NoPreference;
-    case Qt::ColorScheme::Light:
-        return XDG_ColorScheme::PreferLight;
-    case Qt::ColorScheme::Dark:
-        return XDG_ColorScheme::PreferDark;
-    default:
-        Q_UNREACHABLE_RETURN(XDG_ColorScheme::NoPreference);
-        break;
-    }
-}
-
-class DBusInterface
-{
-    DBusInterface() = delete;
-
-    constexpr static auto Service = "org.freedesktop.portal.Desktop"_L1;
-    constexpr static auto Path = "/org/freedesktop/portal/desktop"_L1;
-
-public:
-    static inline QVariant query(QLatin1StringView interface, QLatin1StringView method,
-                                 QLatin1StringView name_space, QLatin1StringView key);
-    static inline uint queryPortalVersion();
-    static inline QLatin1StringView readOneMethod();
-    static inline std::optional<Qt::ColorScheme> queryColorScheme();
-    static inline std::optional<Qt::ContrastPreference> queryContrast();
-};
-
-QVariant DBusInterface::query(QLatin1StringView interface, QLatin1StringView method,
-                              QLatin1StringView name_space, QLatin1StringView key)
-{
-    QDBusConnection dbus = QDBusConnection::sessionBus();
-    if (dbus.isConnected()) {
-        QDBusMessage message = QDBusMessage::createMethodCall(
-                DBusInterface::Service, DBusInterface::Path, interface, method);
-        message << name_space << key;
-
-        QDBusReply<QVariant> reply = dbus.call(message);
-        if (Q_LIKELY(reply.isValid()))
-            return reply.value();
-    } else {
-        qCWarning(lcQpaThemeGnome) << "dbus connection failed. Last error: " << dbus.lastError();
-    }
-
-    return {};
-}
-
-uint DBusInterface::queryPortalVersion()
-{
-    constexpr auto interface = "org.freedesktop.DBus.Properties"_L1;
-    constexpr auto method = "Get"_L1;
-    constexpr auto name_space = "org.freedesktop.portal.Settings"_L1;
-    constexpr auto key = "version"_L1;
-
-    static uint version = 0; // cached version value
-
-    if (version == 0) {
-        QVariant reply = query(interface, method, name_space, key);
-        if (reply.isValid())
-            version = reply.toUInt(); // caches the value for the next calls
-    }
-
-    return version;
-}
-
-QLatin1StringView DBusInterface::readOneMethod()
-{
-    // Based on the documentation on flatpak:
-    // https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.freedesktop.portal.Settings.html
-    // The method name "Read" has changed to "ReadOne" since version 2.
-    const uint version = queryPortalVersion();
-    if (version == 1)
-        return "Read"_L1;
-    return "ReadOne"_L1;
-}
-
-std::optional<Qt::ColorScheme> DBusInterface::queryColorScheme()
-{
-    constexpr auto interface = "org.freedesktop.portal.Settings"_L1;
-    constexpr auto name_space = "org.freedesktop.appearance"_L1;
-    constexpr auto key = "color-scheme"_L1;
-    const auto method = readOneMethod();
-
-    QVariant reply = query(interface, method, name_space, key);
-    if (reply.isValid())
-        return convertColorScheme(
-                XDG_ColorScheme{ reply.value<QDBusVariant>().variant().toUInt() });
-
-    return {};
-}
-
-std::optional<Qt::ContrastPreference> DBusInterface::queryContrast()
-{
-    constexpr auto interface = "org.freedesktop.portal.Settings"_L1;
-    const auto method = readOneMethod();
-
-    constexpr auto namespace_xdg_portal = "org.freedesktop.appearance"_L1;
-    constexpr auto key_xdg_portal = "contrast"_L1;
-    QVariant reply = query(interface, method, namespace_xdg_portal, key_xdg_portal);
-    if (reply.isValid())
-        return static_cast<Qt::ContrastPreference>(reply.toUInt());
-
-    // Fall back to desktop-specific methods (GSettings for GNOME)
-    constexpr auto namespace_gsettings = "org.gnome.desktop.a11y.interface"_L1;
-    constexpr auto key_gsettings = "high-contrast"_L1;
-    reply = query(interface, method, namespace_gsettings, key_gsettings);
-    if (reply.isValid())
-        return reply.toBool() ? Qt::ContrastPreference::HighContrast
-                              : Qt::ContrastPreference::NoPreference;
-
-    return {};
-}
-} // namespace
-
-#endif // QT_CONFIG(dbus)
-
 /*!
     \class QGnomeTheme
     \brief QGnomeTheme is a theme implementation for the Gnome desktop.
@@ -174,13 +24,8 @@ const char *QGnomeTheme::name = "gnome";
 QGnomeThemePrivate::QGnomeThemePrivate()
 {
 #if QT_CONFIG(dbus)
-    initDbus();
-
-    if (auto value = DBusInterface::queryColorScheme(); value.has_value())
-        updateColorScheme(value.value());
-
-    if (auto value = DBusInterface::queryContrast(); value.has_value())
-        updateHighContrast(value.value());
+    QObject::connect(&m_gnomePortal, &QGnomePortalInterface::themeNameChanged, &m_gnomePortal,
+                     [this](const QString &themeName) { m_themeName = themeName; });
 #endif // QT_CONFIG(dbus)
 }
 
@@ -205,43 +50,15 @@ void QGnomeThemePrivate::configureFonts(const QString &gtkFontName) const
     qCDebug(lcQpaFonts) << "default fonts: system" << systemFont << "fixed" << fixedFont;
 }
 
-#if QT_CONFIG(dbus)
-bool QGnomeThemePrivate::initDbus()
-{
-    dbus.reset(new QDBusListener());
-    Q_ASSERT(dbus);
-
-    // Wrap slot in a lambda to avoid inheriting QGnomeThemePrivate from QObject
-    auto wrapper = [this](QDBusListener::Provider provider,
-                          QDBusListener::Setting setting,
-                          const QVariant &value) {
-        if (provider != QDBusListener::Provider::Gnome
-            && provider != QDBusListener::Provider::Gtk) {
-            return;
-        }
-
-        switch (setting) {
-        case QDBusListener::Setting::ColorScheme:
-            updateColorScheme(convertColorScheme(XDG_ColorScheme{ value.toUInt() }));
-            break;
-        case QDBusListener::Setting::Theme:
-            m_themeName = value.toString();
-            break;
-        case QDBusListener::Setting::Contrast:
-            updateHighContrast(value.value<Qt::ContrastPreference>());
-            break;
-        default:
-            break;
-        }
-    };
-
-    return QObject::connect(dbus.get(), &QDBusListener::settingChanged, dbus.get(), wrapper);
-}
-
 Qt::ColorScheme QGnomeThemePrivate::colorScheme() const
 {
-    if (m_colorScheme != Qt::ColorScheme::Unknown)
-        return m_colorScheme;
+    if (hasRequestedColorScheme())
+        return m_requestedColorScheme;
+
+#if QT_CONFIG(dbus)
+    if (Qt::ColorScheme colorScheme = m_gnomePortal.colorScheme();
+        colorScheme != Qt::ColorScheme::Unknown)
+        return colorScheme;
 
     // If the color scheme is set to Unknown by mistake or is not set at all,
     // then maybe the theme name contains a hint about the color scheme.
@@ -251,31 +68,31 @@ Qt::ColorScheme QGnomeThemePrivate::colorScheme() const
         return Qt::ColorScheme::Light;
     else if (m_themeName.contains(QLatin1StringView("dark"), Qt::CaseInsensitive))
         return Qt::ColorScheme::Dark;
-    else
-        return Qt::ColorScheme::Unknown;
-}
-
-void QGnomeThemePrivate::updateColorScheme(Qt::ColorScheme colorScheme)
-{
-    if (m_colorScheme == colorScheme)
-        return;
-    m_colorScheme = colorScheme;
-    QWindowSystemInterface::handleThemeChange();
-}
-
-void QGnomeThemePrivate::updateHighContrast(Qt::ContrastPreference contrast)
-{
-    if (m_contrast == contrast)
-        return;
-    m_contrast = contrast;
-    QWindowSystemInterface::handleThemeChange();
-}
-
 #endif // QT_CONFIG(dbus)
 
+    // Fallback to Unknown if no color scheme is set or detected
+    return Qt::ColorScheme::Unknown;
+}
+
+bool QGnomeThemePrivate::hasRequestedColorScheme() const
+{
+    return m_requestedColorScheme != Qt::ColorScheme::Unknown;
+}
+
 QGnomeTheme::QGnomeTheme()
     : QGenericUnixTheme(new QGnomeThemePrivate())
 {
+#if QT_CONFIG(dbus)
+    Q_D(QGnomeTheme);
+
+    QGnomePortalInterface *portal = &d->m_gnomePortal;
+
+    QObject::connect(portal, &QGnomePortalInterface::colorSchemeChanged, portal,
+                     [this](Qt::ColorScheme colorScheme) { updateColorScheme(colorScheme); });
+
+    QObject::connect(portal, &QGnomePortalInterface::contrastChanged, portal,
+                     [this](Qt::ContrastPreference contrast) { updateHighContrast(contrast); });
+#endif // QT_CONFIG(dbus)
 }
 
 QVariant QGnomeTheme::themeHint(QPlatformTheme::ThemeHint hint) const
@@ -352,7 +169,38 @@ QString QGnomeTheme::gtkFontName() const
                                   .arg(defaultSystemFontSize);
 }
 
+void QGnomeTheme::requestColorScheme(Qt::ColorScheme scheme)
+{
+    Q_D(QGnomeTheme);
+    if (d->m_requestedColorScheme == scheme)
+        return;
+    QPlatformTheme::requestColorScheme(scheme);
+    d->m_requestedColorScheme = scheme;
+    QWindowSystemInterface::handleThemeChange();
+}
+
+Qt::ColorScheme QGnomeTheme::colorScheme() const
+{
+    Q_D(const QGnomeTheme);
+    if (auto colorScheme = d->colorScheme(); colorScheme != Qt::ColorScheme::Unknown)
+        return colorScheme;
+    // If the color scheme is not set or detected, fall back to the default
+    return QPlatformTheme::colorScheme();
+}
+
 #if QT_CONFIG(dbus)
+void QGnomeTheme::updateColorScheme(Qt::ColorScheme colorScheme)
+{
+    Q_UNUSED(colorScheme);
+    QWindowSystemInterface::handleThemeChange();
+}
+
+void QGnomeTheme::updateHighContrast(Qt::ContrastPreference contrast)
+{
+    Q_UNUSED(contrast);
+    QWindowSystemInterface::handleThemeChange();
+}
+
 QPlatformMenuBar *QGnomeTheme::createPlatformMenuBar() const
 {
     if (isDBusGlobalMenuAvailable())
@@ -360,26 +208,21 @@ QPlatformMenuBar *QGnomeTheme::createPlatformMenuBar() const
     return nullptr;
 }
 
-Qt::ColorScheme QGnomeTheme::colorScheme() const
-{
-    return d_func()->colorScheme();
-}
-
 Qt::ContrastPreference QGnomeTheme::contrastPreference() const
 {
-    return d_func()->m_contrast;
+    Q_D(const QGnomeTheme);
+    return d->m_gnomePortal.contrastPreference();
 }
 
-#endif
-
-#if QT_CONFIG(dbus) && QT_CONFIG(systemtrayicon)
+#  if QT_CONFIG(systemtrayicon)
 QPlatformSystemTrayIcon *QGnomeTheme::createPlatformSystemTrayIcon() const
 {
     if (shouldUseDBusTray())
         return new QDBusTrayIcon();
     return nullptr;
 }
-#endif
+#  endif // QT_CONFIG(systemtrayicon)
+#endif // QT_CONFIG(dbus)
 
 QString QGnomeTheme::standardButtonText(int button) const
 {
diff --git a/src/gui/platform/unix/qgnometheme_p.h b/src/gui/platform/unix/qgnometheme_p.h
index 9c59646c715..17b91931876 100644
--- a/src/gui/platform/unix/qgnometheme_p.h
+++ b/src/gui/platform/unix/qgnometheme_p.h
@@ -19,17 +19,19 @@
 #include <qpa/qplatformtheme.h>
 #include <qpa/qplatformtheme_p.h>
 #include <QtGui/QFont>
+#if QT_CONFIG(dbus)
+#  include "qgnomeportalinterface_p.h"
+#endif // QT_CONFIG(dbus)
 
 QT_BEGIN_NAMESPACE
+
 class QGnomeThemePrivate;
-#if QT_CONFIG(dbus)
-class QDBusListener;
-class QDBusPendingCallWatcher;
-#endif
 
 class Q_GUI_EXPORT QGnomeTheme : public QGenericUnixTheme
 {
+protected:
     Q_DECLARE_PRIVATE(QGnomeTheme)
+
 public:
     QGnomeTheme();
     QVariant themeHint(ThemeHint hint) const override;
@@ -39,47 +41,51 @@ public:
     QString standardButtonText(int button) const override;
 
     virtual QString gtkFontName() const;
+
+    virtual void requestColorScheme(Qt::ColorScheme) override;
+    virtual Qt::ColorScheme colorScheme() const override;
+
 #if QT_CONFIG(dbus)
+protected:
+    virtual void updateColorScheme(Qt::ColorScheme);
+    virtual void updateHighContrast(Qt::ContrastPreference);
+
+public:
     QPlatformMenuBar *createPlatformMenuBar() const override;
-    Qt::ColorScheme colorScheme() const override;
     Qt::ContrastPreference contrastPreference() const override;
-#endif
-#if QT_CONFIG(dbus) && QT_CONFIG(systemtrayicon)
+
+#  if QT_CONFIG(systemtrayicon)
     QPlatformSystemTrayIcon *createPlatformSystemTrayIcon() const override;
-#endif
+#  endif // QT_CONFIG(systemtrayicon)
+#endif // QT_CONFIG(dbus)
 
     static const char *name;
 };
 
-class QGnomeThemePrivate : public QGenericUnixThemePrivate
+class Q_GUI_EXPORT QGnomeThemePrivate : public QGenericUnixThemePrivate
 {
+    friend QGnomeTheme;
+
 public:
     QGnomeThemePrivate();
     ~QGnomeThemePrivate();
 
     void configureFonts(const QString &gtkFontName) const;
 
+    Qt::ColorScheme colorScheme() const;
+    bool hasRequestedColorScheme() const;
+
+private:
     mutable QFont *systemFont = nullptr;
     mutable QFont *fixedFont = nullptr;
 
+    Qt::ColorScheme m_requestedColorScheme = Qt::ColorScheme::Unknown;
+
 #if QT_CONFIG(dbus)
-    Qt::ColorScheme m_colorScheme = Qt::ColorScheme::Unknown;
-    Qt::ContrastPreference m_contrast = Qt::ContrastPreference::NoPreference;
-private:
-    std::unique_ptr<QDBusListener> dbus;
-    std::unique_ptr<QDBusPendingCallWatcher> pendingCallWatcher;
+    QGnomePortalInterface m_gnomePortal;
     QString m_themeName;
-
-public:
-    Qt::ColorScheme colorScheme() const;
-
-private:
-    bool initDbus();
-    void updateColorScheme(Qt::ColorScheme colorScheme);
-    void updateHighContrast(Qt::ContrastPreference contrast);
 #endif // QT_CONFIG(dbus)
 };
 
-
 QT_END_NAMESPACE
 #endif // QGNOMETHEME_P_H
diff --git a/src/gui/platform/unix/qkdetheme.cpp b/src/gui/platform/unix/qkdetheme.cpp
index c3de0213780..ef1f9b3455c 100644
--- a/src/gui/platform/unix/qkdetheme.cpp
+++ b/src/gui/platform/unix/qkdetheme.cpp
@@ -130,7 +130,7 @@ void QKdeThemePrivate::settingChangedHandler(QDBusListener::Provider provider,
 
     switch (setting) {
     case QDBusListener::Setting::ColorScheme:
-        qCDebug(lcQpaThemeKde) << "KDE color theme changed to:" << value.toUInt();
+        qCDebug(lcQpaThemeKde) << "KDE color theme changed to:" << value.value<Qt::ColorScheme>();
         break;
     case QDBusListener::Setting::Theme:
         qCDebug(lcQpaThemeKde) << "KDE global theme changed to:" << value.toString();
diff --git a/src/plugins/platformthemes/gtk3/CMakeLists.txt b/src/plugins/platformthemes/gtk3/CMakeLists.txt
index 40c425d367a..6b0613b42fb 100644
--- a/src/plugins/platformthemes/gtk3/CMakeLists.txt
+++ b/src/plugins/platformthemes/gtk3/CMakeLists.txt
@@ -37,8 +37,6 @@ qt_internal_add_plugin(QGtk3ThemePlugin
 )
 
 qt_internal_extend_target(QGtk3ThemePlugin CONDITION QT_FEATURE_dbus
-    SOURCES
-        qgtk3portalinterface.cpp
     LIBRARIES
         Qt::DBus
 )
diff --git a/src/plugins/platformthemes/gtk3/qgtk3portalinterface.cpp b/src/plugins/platformthemes/gtk3/qgtk3portalinterface.cpp
deleted file mode 100644
index 1ffdda74fa8..00000000000
--- a/src/plugins/platformthemes/gtk3/qgtk3portalinterface.cpp
+++ /dev/null
@@ -1,123 +0,0 @@
-// Copyright (C) 2024 The Qt Company Ltd.
-// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists purely as an
-// implementation detail.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-#include "qgtk3portalinterface_p.h"
-#include "qgtk3storage_p.h"
-
-#include <QtDBus/QDBusArgument>
-#include <QtDBus/QDBusConnection>
-#include <QtDBus/QDBusMessage>
-#include <QtDBus/QDBusPendingCall>
-#include <QtDBus/QDBusPendingCallWatcher>
-#include <QtDBus/QDBusPendingReply>
-#include <QtDBus/QDBusVariant>
-#include <QtDBus/QtDBus>
-
-QT_BEGIN_NAMESPACE
-
-Q_LOGGING_CATEGORY(lcQGtk3PortalInterface, "qt.qpa.gtk");
-
-using namespace Qt::StringLiterals;
-
-static constexpr QLatin1StringView appearanceInterface("org.freedesktop.appearance");
-static constexpr QLatin1StringView colorSchemeKey("color-scheme");
-
-const QDBusArgument &operator>>(const QDBusArgument &argument, QMap<QString, QVariantMap> &map)
-{
-    argument.beginMap();
-    map.clear();
-
-    while (!argument.atEnd()) {
-        QString key;
-        QVariantMap value;
-        argument.beginMapEntry();
-        argument >> key >> value;
-        argument.endMapEntry();
-        map.insert(key, value);
-    }
-
-    argument.endMap();
-    return argument;
-}
-
-QGtk3PortalInterface::QGtk3PortalInterface(QGtk3Storage *s)
-    : m_storage(s) {
-    qRegisterMetaType<QDBusVariant>();
-    qDBusRegisterMetaType<QMap<QString, QVariantMap>>();
-
-    queryColorScheme();
-
-    if (!s) {
-        qCDebug(lcQGtk3PortalInterface) << "QGtk3PortalInterface instantiated without QGtk3Storage."
-                                        << "No reaction to runtime theme changes.";
-    }
-}
-
-Qt::ColorScheme QGtk3PortalInterface::colorScheme() const
-{
-   return m_colorScheme;
-}
-
-void QGtk3PortalInterface::queryColorScheme() {
-    QDBusConnection connection = QDBusConnection::sessionBus();
-    QDBusMessage message = QDBusMessage::createMethodCall(
-            "org.freedesktop.portal.Desktop"_L1,
-            "/org/freedesktop/portal/desktop"_L1,
-            "org.freedesktop.portal.Settings"_L1, "ReadAll"_L1);
-    message << QStringList{ appearanceInterface };
-
-    QDBusPendingCall pendingCall = connection.asyncCall(message);
-    QDBusPendingCallWatcher *watcher = new QDBusPendingCallWatcher(pendingCall, this);
-    QObject::connect(
-            watcher, &QDBusPendingCallWatcher::finished, this,
-            [this](QDBusPendingCallWatcher *watcher) {
-                QDBusPendingReply<QMap<QString, QVariantMap>> reply = *watcher;
-                if (reply.isValid()) {
-                    QMap<QString, QVariantMap> settings = reply.value();
-                    if (!settings.isEmpty()) {
-                        settingChanged(appearanceInterface, colorSchemeKey,
-                                       QDBusVariant(settings.value(appearanceInterface).value(colorSchemeKey)));
-                    }
-                } else {
-                    qCDebug(lcQGtk3PortalInterface) << "Failed to query org.freedesktop.portal.Settings: "
-                                                    << reply.error().message();
-                }
-                watcher->deleteLater();
-            });
-
-    QDBusConnection::sessionBus().connect(
-            "org.freedesktop.portal.Desktop"_L1, "/org/freedesktop/portal/desktop"_L1,
-            "org.freedesktop.portal.Settings"_L1, "SettingChanged"_L1, this,
-            SLOT(settingChanged(QString, QString, QDBusVariant)));
-}
-
-void QGtk3PortalInterface::settingChanged(const QString &group, const QString &key,
-                                          const QDBusVariant &value)
-{
-    if (group == appearanceInterface && key == colorSchemeKey) {
-        const uint colorScheme = value.variant().toUInt();
-        // From org.freedesktop.portal.Settings.xml
-        // "1" - Prefer dark appearance
-        Qt::ColorScheme newColorScheme = colorScheme == 1 ? Qt::ColorScheme::Dark : Qt::ColorScheme::Light;
-        if (m_colorScheme != newColorScheme) {
-            m_colorScheme = newColorScheme;
-            if (m_storage)
-                m_storage->handleThemeChange();
-        }
-    }
-}
-
-QT_END_NAMESPACE
-
-#include "moc_qgtk3portalinterface_p.cpp"
diff --git a/src/plugins/platformthemes/gtk3/qgtk3portalinterface_p.h b/src/plugins/platformthemes/gtk3/qgtk3portalinterface_p.h
deleted file mode 100644
index 25a5f58ab1a..00000000000
--- a/src/plugins/platformthemes/gtk3/qgtk3portalinterface_p.h
+++ /dev/null
@@ -1,49 +0,0 @@
-// Copyright (C) 2024 The Qt Company Ltd.
-// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
-
-#ifndef QGTK3PORTALINTERFACE_H
-#define QGTK3PORTALINTERFACE_H
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists purely as an
-// implementation detail.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-#include <QtCore/QObject>
-#include <QtCore/QLoggingCategory>
-
-QT_BEGIN_NAMESPACE
-
-class QDBusVariant;
-class QGtk3Storage;
-
-Q_DECLARE_LOGGING_CATEGORY(lcQGtk3PortalInterface);
-
-class QGtk3PortalInterface : public QObject
-{
-    Q_OBJECT
-public:
-    QGtk3PortalInterface(QGtk3Storage *s);
-    ~QGtk3PortalInterface() = default;
-
-    Qt::ColorScheme colorScheme() const;
-
-private Q_SLOTS:
-    void settingChanged(const QString &group, const QString &key,
-                        const QDBusVariant &value);
-private:
-    void queryColorScheme();
-
-    Qt::ColorScheme m_colorScheme = Qt::ColorScheme::Unknown;
-    QGtk3Storage *m_storage = nullptr;
-};
-
-QT_END_NAMESPACE
-
-#endif // QGTK3PORTALINTERFACE_H
diff --git a/src/plugins/platformthemes/gtk3/qgtk3storage.cpp b/src/plugins/platformthemes/gtk3/qgtk3storage.cpp
index 2991212d033..ae4502183da 100644
--- a/src/plugins/platformthemes/gtk3/qgtk3storage.cpp
+++ b/src/plugins/platformthemes/gtk3/qgtk3storage.cpp
@@ -15,6 +15,9 @@
 #include "qgtk3json_p.h"
 #include "qgtk3storage_p.h"
 #include <qpa/qwindowsysteminterface.h>
+#if QT_CONFIG(dbus)
+#  include <QtGui/private/qgnomeportalinterface_p.h>
+#endif
 
 QT_BEGIN_NAMESPACE
 
@@ -22,11 +25,13 @@ QGtk3Storage::QGtk3Storage()
 {
     m_interface.reset(new QGtk3Interface(this));
 #if QT_CONFIG(dbus)
-    m_portalInterface.reset(new QGtk3PortalInterface(this));
+    m_portalInterface.reset(new QGnomePortalInterface);
 #endif
     populateMap();
 }
 
+QGtk3Storage::~QGtk3Storage() { }
+
 /*!
     \internal
     \enum QGtk3Storage::SourceType
diff --git a/src/plugins/platformthemes/gtk3/qgtk3storage_p.h b/src/plugins/platformthemes/gtk3/qgtk3storage_p.h
index 002e916377e..d0668a97216 100644
--- a/src/plugins/platformthemes/gtk3/qgtk3storage_p.h
+++ b/src/plugins/platformthemes/gtk3/qgtk3storage_p.h
@@ -16,9 +16,6 @@
 //
 
 #include "qgtk3interface_p.h"
-#if QT_CONFIG(dbus)
-#include "qgtk3portalinterface_p.h"
-#endif
 
 #include <QtCore/QJsonDocument>
 #include <QtCore/QCache>
@@ -30,11 +27,17 @@
 #include <private/qflatmap_p.h>
 
 QT_BEGIN_NAMESPACE
+
+#if QT_CONFIG(dbus)
+class QGnomePortalInterface;
+#endif
+
 class QGtk3Storage
 {
     Q_GADGET
 public:
     QGtk3Storage();
+    ~QGtk3Storage();
 
     // Enum documented in cpp file. Please keep it in line with updates made here.
     enum class SourceType {
@@ -242,7 +245,7 @@ private:
 
     std::unique_ptr<QGtk3Interface> m_interface;
 #if QT_CONFIG(dbus)
-    std::unique_ptr<QGtk3PortalInterface> m_portalInterface;
+    std::unique_ptr<QGnomePortalInterface> m_portalInterface;
 #endif
 
     Qt::ColorScheme m_colorScheme = Qt::ColorScheme::Unknown;
diff --git a/src/plugins/platformthemes/gtk3/qgtk3theme.cpp b/src/plugins/platformthemes/gtk3/qgtk3theme.cpp
index c1c1e623a27..c720fc41dbd 100644
--- a/src/plugins/platformthemes/gtk3/qgtk3theme.cpp
+++ b/src/plugins/platformthemes/gtk3/qgtk3theme.cpp
@@ -163,29 +163,34 @@ QString QGtk3Theme::gtkFontName() const
     return QGnomeTheme::gtkFontName();
 }
 
-void QGtk3Theme::requestColorScheme(Qt::ColorScheme scheme)
-{
-    if (m_requestedColorScheme == scheme)
-        return;
-    qCDebug(lcQGtk3Interface) << scheme << "has been requested. Theme supports color scheme:"
-                              << m_storage->colorScheme();
-    QPlatformTheme::requestColorScheme(scheme);
-    m_requestedColorScheme = scheme;
-    m_storage->handleThemeChange();
-}
-
 Qt::ColorScheme QGtk3Theme::colorScheme() const
 {
     Q_ASSERT(m_storage);
+
+    Q_D(const QGnomeTheme);
+    const Qt::ColorScheme colorScheme = d->colorScheme();
+    const bool hasRequestedColorScheme = d->hasRequestedColorScheme();
+
 #ifdef QT_DEBUG
-    if (m_requestedColorScheme != Qt::ColorScheme::Unknown
-        && m_requestedColorScheme != m_storage->colorScheme()) {
-        qCDebug(lcQGtk3Interface) << "Requested color scheme" << m_requestedColorScheme
+    if (hasRequestedColorScheme && colorScheme != m_storage->colorScheme()) {
+        qCDebug(lcQGtk3Interface) << "Requested color scheme" << colorScheme
                                   << "differs from theme color scheme" << m_storage->colorScheme();
     }
 #endif
-    return m_requestedColorScheme == Qt::ColorScheme::Unknown ? m_storage->colorScheme()
-                                                              : m_requestedColorScheme;
+
+    return hasRequestedColorScheme ? colorScheme : m_storage->colorScheme();
+}
+
+void QGtk3Theme::requestColorScheme(Qt::ColorScheme scheme)
+{
+    const Qt::ColorScheme oldColorScheme = colorScheme();
+    QGnomeTheme::requestColorScheme(scheme);
+    if (oldColorScheme == colorScheme())
+        return;
+    qCDebug(lcQGtk3Interface) << scheme << "has been requested. Theme supports color scheme:"
+                              << m_storage->colorScheme();
+    m_storage->handleThemeChange();
+    QWindowSystemInterface::sendWindowSystemEvents(QEventLoop::AllEvents);
 }
 
 bool QGtk3Theme::usePlatformNativeDialog(DialogType type) const
@@ -234,18 +239,22 @@ bool QGtk3Theme::useNativeFileDialog()
 const QPalette *QGtk3Theme::palette(Palette type) const
 {
     Q_ASSERT(m_storage);
+
+    Q_D(const QGnomeTheme);
+    const Qt::ColorScheme colorScheme = d->colorScheme();
+    const bool hasRequestedColorScheme = d->hasRequestedColorScheme();
+
 #ifdef QT_DEBUG
-    if (m_requestedColorScheme != Qt::ColorScheme::Unknown
-        && m_requestedColorScheme != m_storage->colorScheme()) {
+    if (hasRequestedColorScheme && colorScheme != m_storage->colorScheme()) {
         qCDebug(lcQGtk3Interface) << "Current KDE theme doesn't support requested color scheme"
-                                  << m_requestedColorScheme << "Falling back to fusion palette.";
+                                  << colorScheme << "Falling back to fusion palette.";
         return QPlatformTheme::palette(type);
     }
 #endif
 
-    return (m_requestedColorScheme != Qt::ColorScheme::Unknown
-            && m_requestedColorScheme != m_storage->colorScheme())
-               ? QPlatformTheme::palette(type) : m_storage->palette(type);
+    return (hasRequestedColorScheme && colorScheme != m_storage->colorScheme())
+            ? QPlatformTheme::palette(type)
+            : m_storage->palette(type);
 }
 
 QPixmap QGtk3Theme::standardPixmap(StandardPixmap sp, const QSizeF &size) const
@@ -268,4 +277,14 @@ QIcon QGtk3Theme::fileIcon(const QFileInfo &fileInfo,
     return m_storage->fileIcon(fileInfo);
 }
 
+#if QT_CONFIG(dbus)
+void QGtk3Theme::updateColorScheme(Qt::ColorScheme newColorScheme)
+{
+    if (newColorScheme == colorScheme())
+        QGnomeTheme::updateColorScheme(newColorScheme);
+    else
+        m_storage->handleThemeChange();
+}
+#endif // QT_CONFIG(dbus)
+
 QT_END_NAMESPACE
diff --git a/src/plugins/platformthemes/gtk3/qgtk3theme.h b/src/plugins/platformthemes/gtk3/qgtk3theme.h
index d2f2efff51f..ce7dc9c9dc8 100644
--- a/src/plugins/platformthemes/gtk3/qgtk3theme.h
+++ b/src/plugins/platformthemes/gtk3/qgtk3theme.h
@@ -31,8 +31,11 @@ public:
                            QPlatformTheme::IconOptions iconOptions = { }) const override;
 
     static const char *name;
+
 private:
-    Qt::ColorScheme m_requestedColorScheme = Qt::ColorScheme::Unknown;
+#if QT_CONFIG(dbus)
+    void updateColorScheme(Qt::ColorScheme) override;
+#endif // QT_CONFIG(dbus)
     static bool useNativeFileDialog();
     std::unique_ptr<QGtk3Storage> m_storage;
 };