[Bug] SystemThemeWatcher is not working properly

Describe the bug

Some themes, such as Glow, CapturedMotion, Sunrise, and Flow, may not accurately reflect Dark or Light mode because their internal logic is rigidly set.

To Reproduce

Go to Window Settings -> set the theme to Sunrise, then set the color to Dark.

Expected behavior

After delving into the logic of SystemThemeWatcher, I discovered that it uses SystemThemeManager.GetCachedSystemTheme() which only reflects the set theme type and doesn't accurately reflect Dark or Light color.

I want to create another solution to read into

Registry.GetValue(
    @"HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Themes\Personalize",
    "AppsUseLightTheme",
    1
);

Screenshots

OS version

Windows 11 Pro Insider Preview (25H2 Build 26300.8687)

.NET version

.NET 10

WPF-UI NuGet version

4.3.0

Additional context

No response

Start by locating SystemThemeWatcher and tracing its use of SystemThemeManager.GetCachedSystemTheme(). Reproduce the Sunrise theme with Dark color in Windows Settings, then compare the watcher result with the AppsUseLightTheme value from the stated registry location. Done means the affected themes accurately reflect the selected Dark or Light mode.