diff --git a/include/FramelessHelper/Core/utils.h b/include/FramelessHelper/Core/utils.h
index a569d6b..97421ab 100644
--- a/include/FramelessHelper/Core/utils.h
+++ b/include/FramelessHelper/Core/utils.h
@@ -52,7 +52,6 @@ FRAMELESSHELPER_CORE_API void startSystemResize(QWindow *window, const Qt::Edges
 [[nodiscard]] FRAMELESSHELPER_CORE_API QWindow *findWindow(const WId windowId);
 FRAMELESSHELPER_CORE_API void moveWindowToDesktopCenter(
     const SystemParameters *params, const bool considerTaskBar);
-[[nodiscard]] FRAMELESSHELPER_CORE_API Global::SystemTheme getSystemTheme();
 [[nodiscard]] FRAMELESSHELPER_CORE_API Qt::WindowState windowStatesToWindowState(
     const Qt::WindowStates states);
 [[nodiscard]] FRAMELESSHELPER_CORE_API bool isThemeChangeEvent(const QEvent * const event);
@@ -84,6 +83,10 @@ FRAMELESSHELPER_CORE_API void registerThemeChangeNotification();
 [[nodiscard]] FRAMELESSHELPER_CORE_API qreal getRelativeScaleFactor(const quint32 oldDpi, const quint32 newDpi);
 [[nodiscard]] FRAMELESSHELPER_CORE_API QSize rescaleSize(const QSize &oldSize, const quint32 oldDpi, const quint32 newDpi);
 [[nodiscard]] FRAMELESSHELPER_CORE_API bool isValidGeometry(const QRect &rect);
+[[nodiscard]] FRAMELESSHELPER_CORE_API QColor getAccentColor();
+[[nodiscard]] FRAMELESSHELPER_CORE_API quint32 defaultScreenDpi();
+[[nodiscard]] FRAMELESSHELPER_CORE_API qreal getRealDevicePixelRatio(const QWindow *window);
+[[nodiscard]] FRAMELESSHELPER_CORE_API qreal getQtDevicePixelRatio(const QWindow *window);
 
 #ifdef Q_OS_WINDOWS
 [[nodiscard]] FRAMELESSHELPER_CORE_API bool isWindowsVersionOrGreater(const Global::WindowsVersion version);
@@ -125,8 +128,8 @@ FRAMELESSHELPER_CORE_API void setAeroSnappingEnabled(const WId windowId, const b
 FRAMELESSHELPER_CORE_API void tryToEnableHighestDpiAwarenessLevel();
 FRAMELESSHELPER_CORE_API void updateGlobalWin32ControlsTheme(const WId windowId, const bool dark);
 [[nodiscard]] FRAMELESSHELPER_CORE_API bool shouldAppsUseDarkMode_windows();
+[[nodiscard]] FRAMELESSHELPER_CORE_API QColor getAccentColor_windows();
 FRAMELESSHELPER_CORE_API void setCornerStyleForWindow(const WId windowId, const Global::WindowCornerStyle style);
-[[nodiscard]] FRAMELESSHELPER_CORE_API QColor getDwmAccentColor();
 FRAMELESSHELPER_CORE_API void hideOriginalTitleBarElements
     (const WId windowId, const bool disable = true);
 FRAMELESSHELPER_CORE_API void setQtDarkModeAwareEnabled(const bool enable);
@@ -168,7 +171,7 @@ FRAMELESSHELPER_CORE_API void clearWindowProperty(const WId windowId, const xcb_
 [[nodiscard]] FRAMELESSHELPER_CORE_API bool tryHideSystemTitleBar(const WId windowId, const bool hide = true);
 FRAMELESSHELPER_CORE_API void openSystemMenu(const WId windowId, const QPoint &globalPos);
 [[nodiscard]] FRAMELESSHELPER_CORE_API bool shouldAppsUseDarkMode_linux();
-[[nodiscard]] FRAMELESSHELPER_CORE_API QColor getWmThemeColor();
+[[nodiscard]] FRAMELESSHELPER_CORE_API QColor getAccentColor_linux();
 FRAMELESSHELPER_CORE_API void sendMoveResizeMessage
     (const WId windowId, const uint32_t action, const QPoint &globalPos, const Qt::MouseButton button = Qt::LeftButton);
 [[nodiscard]] FRAMELESSHELPER_CORE_API bool isCustomDecorationSupported();
@@ -178,8 +181,8 @@ FRAMELESSHELPER_CORE_API void sendMoveResizeMessage
 
 #ifdef Q_OS_MACOS
 [[nodiscard]] FRAMELESSHELPER_CORE_API bool shouldAppsUseDarkMode_macos();
+[[nodiscard]] FRAMELESSHELPER_CORE_API QColor getAccentColor_macos();
 FRAMELESSHELPER_CORE_API void setSystemTitleBarVisible(const WId windowId, const bool visible);
-[[nodiscard]] FRAMELESSHELPER_CORE_API QColor getControlsAccentColor();
 FRAMELESSHELPER_CORE_API void removeWindowProxy(const WId windowId);
 #endif // Q_OS_MACOS
 } // namespace Utils
diff --git a/src/core/chromepalette.cpp b/src/core/chromepalette.cpp
index ef66180..20ee2cb 100644
--- a/src/core/chromepalette.cpp
+++ b/src/core/chromepalette.cpp
@@ -84,15 +84,7 @@ void ChromePalettePrivate::refresh()
     const bool dark = (FramelessManager::instance()->systemTheme() == SystemTheme::Dark);
     titleBarActiveBackgroundColor_sys = [colorized, dark]() -> QColor {
         if (colorized) {
-#ifdef Q_OS_WINDOWS
-            return Utils::getDwmAccentColor();
-#elif defined(Q_OS_LINUX)
-            return Utils::getWmThemeColor();
-#elif defined(Q_OS_MACOS)
-            return Utils::getControlsAccentColor();
-#else
-            return {};
-#endif
+            return Utils::getAccentColor();
         } else {
             return (dark ? kDefaultBlackColor : kDefaultWhiteColor);
         }
diff --git a/src/core/framelesshelpercore_global.cpp b/src/core/framelesshelpercore_global.cpp
index 9bbeff6..1f09a70 100644
--- a/src/core/framelesshelpercore_global.cpp
+++ b/src/core/framelesshelpercore_global.cpp
@@ -86,12 +86,7 @@ QDebug operator<<(QDebug d, const FRAMELESSHELPER_PREPEND_NAMESPACE(Global)::Ver
 QDebug operator<<(QDebug d, const FRAMELESSHELPER_PREPEND_NAMESPACE(Global)::Dpi &dpi)
 {
     const QDebugStateSaver saver(d);
-#ifdef Q_OS_MACOS
-    static constexpr const auto defaultDpi = quint32(72);
-#else // !Q_OS_MACOS
-    static constexpr const auto defaultDpi = quint32(96);
-#endif // Q_OS_MACOS
-    const qreal scaleFactor = (qreal(dpi.x) / qreal(defaultDpi));
+    const qreal scaleFactor = (qreal(dpi.x) / qreal(FRAMELESSHELPER_PREPEND_NAMESPACE(Utils)::defaultScreenDpi()));
     d.nospace().noquote() << "Dpi("
                           << "x: " << dpi.x << ", "
                           << "y: " << dpi.y << ", "
diff --git a/src/core/framelessmanager.cpp b/src/core/framelessmanager.cpp
index a1cdbfe..c409bf9 100644
--- a/src/core/framelessmanager.cpp
+++ b/src/core/framelessmanager.cpp
@@ -238,16 +238,10 @@ void FramelessManagerPrivate::removeWindow(const WId windowId)
 
 void FramelessManagerPrivate::notifySystemThemeHasChangedOrNot()
 {
-    const SystemTheme currentSystemTheme = Utils::getSystemTheme();
+    const SystemTheme currentSystemTheme = (Utils::shouldAppsUseDarkMode() ? SystemTheme::Dark : SystemTheme::Light);
+    const QColor currentAccentColor = Utils::getAccentColor();
 #ifdef Q_OS_WINDOWS
     const DwmColorizationArea currentColorizationArea = Utils::getDwmColorizationArea();
-    const QColor currentAccentColor = Utils::getDwmAccentColor();
-#endif
-#ifdef Q_OS_LINUX
-    const QColor currentAccentColor = Utils::getWmThemeColor();
-#endif
-#ifdef Q_OS_MACOS
-    const QColor currentAccentColor = Utils::getControlsAccentColor();
 #endif
     bool notify = false;
     if (m_systemTheme != currentSystemTheme) {
@@ -332,16 +326,10 @@ bool FramelessManagerPrivate::isThemeOverrided() const
 
 void FramelessManagerPrivate::initialize()
 {
-    m_systemTheme = Utils::getSystemTheme();
+    m_systemTheme = (Utils::shouldAppsUseDarkMode() ? SystemTheme::Dark : SystemTheme::Light);
+    m_accentColor = Utils::getAccentColor();
 #ifdef Q_OS_WINDOWS
     m_colorizationArea = Utils::getDwmColorizationArea();
-    m_accentColor = Utils::getDwmAccentColor();
-#endif
-#ifdef Q_OS_LINUX
-    m_accentColor = Utils::getWmThemeColor();
-#endif
-#ifdef Q_OS_MACOS
-    m_accentColor = Utils::getControlsAccentColor();
 #endif
     m_wallpaper = Utils::getWallpaperFilePath();
     m_wallpaperAspectStyle = Utils::getWallpaperAspectStyle();
diff --git a/src/core/utils.cpp b/src/core/utils.cpp
index 20a04d5..d6231bf 100644
--- a/src/core/utils.cpp
+++ b/src/core/utils.cpp
@@ -32,6 +32,7 @@
 #include <QtGui/qscreen.h>
 #include <QtGui/qguiapplication.h>
 #include <QtGui/qfontmetrics.h>
+#include <QtGui/qpalette.h>
 #ifndef FRAMELESSHELPER_CORE_NO_PRIVATE
 #  include <QtGui/private/qhighdpiscaling_p.h>
 #endif // FRAMELESSHELPER_CORE_NO_PRIVATE
@@ -276,15 +277,7 @@ QColor Utils::calculateSystemButtonBackgroundColor(const SystemButtonType button
             return kDefaultSystemCloseButtonBackgroundColor;
         }
         if (isTitleColor) {
-#ifdef Q_OS_WINDOWS
-            return getDwmAccentColor();
-#endif
-#ifdef Q_OS_LINUX
-            return getWmThemeColor();
-#endif
-#ifdef Q_OS_MACOS
-            return getControlsAccentColor();
-#endif
+            return getAccentColor();
         }
         return kDefaultSystemButtonBackgroundColor;
     }();
@@ -527,11 +520,7 @@ qreal Utils::getRelativeScaleFactor(const quint32 oldDpi, const quint32 newDpi)
     if (newDpi == oldDpi) {
         return qreal(1);
     }
-#ifdef Q_OS_MACOS
-    static constexpr const auto defaultDpi = quint32(72);
-#else // !Q_OS_MACOS
-    static constexpr const auto defaultDpi = quint32(96);
-#endif // Q_OS_MACOS
+    static const quint32 defaultDpi = defaultScreenDpi();
     if ((oldDpi < defaultDpi) || (newDpi < defaultDpi)) {
         return qreal(1);
     }
@@ -566,4 +555,50 @@ bool Utils::isValidGeometry(const QRect &rect)
     return ((rect.right() > rect.left()) && (rect.bottom() > rect.top()));
 }
 
+quint32 Utils::defaultScreenDpi()
+{
+#ifdef Q_OS_MACOS
+    return 72;
+#else // !Q_OS_MACOS
+    return 96;
+#endif // Q_OS_MACOS
+}
+
+qreal Utils::getRealDevicePixelRatio(const QWindow *window)
+{
+    Q_ASSERT(window);
+    if (!window) {
+        return qreal(1);
+    }
+    // Qt doesn't support device pixel ratio smaller than 1.
+    return std::max(qreal(getDpiForWindow(window)) / qreal(defaultScreenDpi()), qreal(1));
+}
+
+qreal Utils::getQtDevicePixelRatio(const QWindow *window)
+{
+    Q_ASSERT(window);
+    if (!window) {
+        return qreal(1);
+    }
+    // Apply the rounding policy from Qt, most probably set by the user.
+    return roundScaleFactor(getRealDevicePixelRatio(window));
+}
+
+QColor Utils::getAccentColor()
+{
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 6, 0))
+    return QGuiApplication::palette().color(QPalette::AccentColor);
+#else // (QT_VERSION < QT_VERSION_CHECK(6, 6, 0))
+#  ifdef Q_OS_WINDOWS
+    return getAccentColor_windows();
+#  elif defined(Q_OS_LINUX)
+    return getAccentColor_linux();
+#  elif defined(Q_OS_MACOS)
+    return getAccentColor_macos();
+#  else
+    return QGuiApplication::palette().color(QPalette::Highlight);
+#  endif
+#endif // (QT_VERSION >= QT_VERSION_CHECK(6, 6, 0))
+}
+
 FRAMELESSHELPER_END_NAMESPACE
diff --git a/src/core/utils_linux.cpp b/src/core/utils_linux.cpp
index a049445..0be7415 100644
--- a/src/core/utils_linux.cpp
+++ b/src/core/utils_linux.cpp
@@ -344,12 +344,6 @@ xcb_connection_t *Utils::x11_connection()
 #endif // FRAMELESSHELPER_HAS_X11EXTRAS
 }
 
-SystemTheme Utils::getSystemTheme()
-{
-    // ### TODO: how to detect high contrast mode on Linux?
-    return (shouldAppsUseDarkMode() ? SystemTheme::Dark : SystemTheme::Light);
-}
-
 void Utils::startSystemMove(QWindow *window, const QPoint &globalPos)
 {
     Q_ASSERT(window);
@@ -390,7 +384,7 @@ bool Utils::isTitleBarColorized()
     return false;
 }
 
-QColor Utils::getWmThemeColor()
+QColor Utils::getAccentColor_linux()
 {
     // ### TODO
     return QGuiApplication::palette().color(QPalette::Highlight);
@@ -577,7 +571,7 @@ void Utils::registerThemeChangeNotification()
 
 QColor Utils::getFrameBorderColor(const bool active)
 {
-    return (active ? getWmThemeColor() : kDefaultDarkGrayColor);
+    return (active ? getAccentColor() : kDefaultDarkGrayColor);
 }
 
 xcb_atom_t Utils::internAtom(const char *name)
diff --git a/src/core/utils_mac.mm b/src/core/utils_mac.mm
index b717643..5908d89 100644
--- a/src/core/utils_mac.mm
+++ b/src/core/utils_mac.mm
@@ -615,12 +615,6 @@ static inline void cleanupProxy()
     return g_macUtilsData()->hash.value(windowId);
 }
 
-SystemTheme Utils::getSystemTheme()
-{
-    // ### TODO: how to detect high contrast mode on macOS?
-    return (shouldAppsUseDarkMode() ? SystemTheme::Dark : SystemTheme::Light);
-}
-
 void Utils::setSystemTitleBarVisible(const WId windowId, const bool visible)
 {
     Q_ASSERT(windowId);
@@ -678,7 +672,7 @@ void Utils::startSystemResize(QWindow *window, const Qt::Edges edges, const QPoi
 #endif
 }
 
-QColor Utils::getControlsAccentColor()
+QColor Utils::getAccentColor_macos()
 {
     return qt_mac_toQColor([NSColor controlAccentColor]);
 }
@@ -793,7 +787,7 @@ void Utils::removeWindowProxy(const WId windowId)
 
 QColor Utils::getFrameBorderColor(const bool active)
 {
-    return (active ? getControlsAccentColor() : kDefaultDarkGrayColor);
+    return (active ? getAccentColor() : kDefaultDarkGrayColor);
 }
 
 FRAMELESSHELPER_END_NAMESPACE
diff --git a/src/core/utils_win.cpp b/src/core/utils_win.cpp
index 4583ea8..c2607e9 100644
--- a/src/core/utils_win.cpp
+++ b/src/core/utils_win.cpp
@@ -1262,10 +1262,10 @@ QColor Utils::getFrameBorderColor(const bool active)
     if (!WindowsVersionHelper::isWin10OrGreater()) {
         return (active ? kDefaultBlackColor : kDefaultDarkGrayColor);
     }
-    const bool dark = shouldAppsUseDarkMode();
+    const bool dark = (FramelessManager::instance()->systemTheme() == SystemTheme::Dark);
     if (active) {
         if (isFrameBorderColorized()) {
-            return getDwmAccentColor();
+            return getAccentColor();
         }
         return (dark ? kDefaultFrameBorderActiveColor : kDefaultTransparentColor);
     } else {
@@ -1601,17 +1601,6 @@ void Utils::tryToEnableHighestDpiAwarenessLevel()
     }
 }
 
-SystemTheme Utils::getSystemTheme()
-{
-    if (isHighContrastModeEnabled()) {
-        return SystemTheme::HighContrast;
-    }
-    if (WindowsVersionHelper::isWin10RS1OrGreater() && shouldAppsUseDarkMode()) {
-        return SystemTheme::Dark;
-    }
-    return SystemTheme::Light;
-}
-
 void Utils::updateGlobalWin32ControlsTheme(const WId windowId, const bool dark)
 {
     Q_ASSERT(windowId);
@@ -1636,7 +1625,7 @@ void Utils::updateGlobalWin32ControlsTheme(const WId windowId, const bool dark)
 bool Utils::shouldAppsUseDarkMode_windows()
 {
     // The global dark mode was first introduced in Windows 10 1607.
-    if (!WindowsVersionHelper::isWin10RS1OrGreater()) {
+    if (!WindowsVersionHelper::isWin10RS1OrGreater() || isHighContrastModeEnabled()) {
         return false;
     }
 #ifndef FRAMELESSHELPER_CORE_NO_PRIVATE
@@ -1856,7 +1845,7 @@ bool Utils::setBlurBehindWindowEnabled(const WId windowId, const BlurMode mode,
                         if (color.isValid()) {
                             return color;
                         }
-                        QColor clr = (shouldAppsUseDarkMode() ? kDefaultSystemDarkColor : kDefaultSystemLightColor);
+                        QColor clr = ((FramelessManager::instance()->systemTheme() == SystemTheme::Dark) ? kDefaultSystemDarkColor : kDefaultSystemLightColor);
                         clr.setAlphaF(0.9f);
                         return clr;
                     }();
@@ -1917,9 +1906,9 @@ bool Utils::setBlurBehindWindowEnabled(const WId windowId, const BlurMode mode,
     return false;
 }
 
-QColor Utils::getDwmAccentColor()
+QColor Utils::getAccentColor_windows()
 {
-    // According to my test, this AccentColor will be exactly the same with
+    // According to my experiments, this AccentColor will be exactly the same with
     // ColorizationColor, what's the meaning of it? But Microsoft products
     // usually read this setting instead of using DwmGetColorizationColor(),
     // so we'd better also do the same thing.
@@ -1935,7 +1924,7 @@ QColor Utils::getDwmAccentColor()
         return alternative;
     }
     // The retrieved value is in the #AABBGGRR format, we need to
-    // convert it to the #AARRGGBB format that Qt accepts.
+    // convert it to the #AARRGGBB format which Qt expects.
     const QColor abgr = QColor::fromRgba(qvariant_cast<DWORD>(value));
     if (!abgr.isValid()) {
         return alternative;
diff --git a/src/quick/framelessquickutils.cpp b/src/quick/framelessquickutils.cpp
index 7cee918..8bdbf30 100644
--- a/src/quick/framelessquickutils.cpp
+++ b/src/quick/framelessquickutils.cpp
@@ -94,15 +94,7 @@ void FramelessQuickUtils::setOverrideTheme(const QuickGlobal::SystemTheme theme)
 
 QColor FramelessQuickUtils::systemAccentColor() const
 {
-#ifdef Q_OS_WINDOWS
-    return Utils::getDwmAccentColor();
-#elif defined(Q_OS_LINUX)
-    return Utils::getWmThemeColor();
-#elif defined(Q_OS_MACOS)
-    return Utils::getControlsAccentColor();
-#else
-    return {};
-#endif
+    return Utils::getAccentColor();
 }
 
 bool FramelessQuickUtils::titleBarColorized() const