Revert "meh"

This reverts commit 9d9204430e.

Source/Core/DolphinQt/MainWindow.cpp

@@ -241,6 +241,11 @@ MainWindow::MainWindow(std::unique_ptr<BootParameters> boot_parameters,
   ConnectMenuBar();
   ConnectHotkeys();
 
+#if QT_VERSION >= QT_VERSION_CHECK(6, 5, 0)
+  connect(QGuiApplication::styleHints(), &QStyleHints::colorSchemeChanged, this,
+          [](Qt::ColorScheme colorScheme) { Settings::Instance().ApplyStyle(); });
+#endif
+
   connect(m_cheats_manager, &CheatsManager::OpenGeneralSettings, this,
           &MainWindow::ShowGeneralWindow);
 
@@ -1860,6 +1865,29 @@ QSize MainWindow::sizeHint() const
 #ifdef _WIN32
 bool MainWindow::nativeEvent(const QByteArray& eventType, void* message, qintptr* result)
 {
+  auto* msg = reinterpret_cast<MSG*>(message);
+  if (msg && msg->message == WM_SETTINGCHANGE && msg->lParam != NULL &&
+      std::wstring_view(L"ImmersiveColorSet")
+              .compare(reinterpret_cast<const wchar_t*>(msg->lParam)) == 0)
+  {
+    // Windows light/dark theme has changed. Update our flag and refresh the theme.
+    auto& settings = Settings::Instance();
+    const bool was_dark_before = settings.IsSystemDark();
+    settings.UpdateSystemDark();
+    if (settings.IsSystemDark() != was_dark_before)
+    {
+      settings.ApplyStyle();
+
+      // force the colors in the Skylander window to update
+      if (m_skylander_window)
+        m_skylander_window->RefreshList();
+    }
+
+    // TODO: When switching from light to dark, the window decorations remain light. Qt seems very
+    // convinced that it needs to change these in response to this message, so even if we set them
+    // to dark here, Qt sets them back to light afterwards.
+  }
+
   return false;
 }
 #endif