[feature request] native windows dark mode system menu

[emako]

Why not using UxTheme #135 for dark mode if OS version >= Windows 10 Version 1809 (Build 17763)?

enum PreferredAppMode { Default = 0, Dark = 1, Light = 2 };
typedef int(WINAPI* SetPreferredAppMode_t)(PreferredAppMode preferredAppMode);

HMODULE hModule = LoadLibrary(L"uxtheme.dll");
if (hModule != NULL) {
    SetPreferredAppMode_t SetPreferredAppMode =
        (SetPreferredAppMode_t)GetProcAddress(hModule, MAKEINTRESOURCEA(135)); // Loading the #135 API
    SetPreferredAppMode(PreferredAppMode::Dark);
    if (SetPreferredAppMode == NULL) {
        FreeLibrary(hModule);
    }
}

Renderings like

(Because the selected darker theme will be overwritten, the screenshot under light is used here.)

instead of