api function to detect light or dark user mode

[AnthonyBall1966]

Here are some notes...

javascript (html5):
if (window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches) {
// dark mode
}

android:
// We load the Night Mode state here
SharedPreferences mPrefs = PreferenceManager.getDefaultSharedPreferences(this);
this.isNightModeEnabled = mPrefs.getBoolean(“NIGHT_MODE”, false);
}

iOS:
https://schiavo.me/2019/implementing-dark-mode/

MacOS:
UserDefaults=CocoaMessage(0,0,"NSUserDefaults standardUserDefaults")
NSstring=CocoaMessage(0,UserDefaults,"stringForKey:$",@"AppleInterfaceStyle")
If NSstring
string$=PeekS(CocoaMessage(0,NSstring,"UTF8String"),-1,#PB_UTF8)
If string$="Dark"
ProcedureReturn #True
Else
ProcedureReturn #False
EndIf
Else
ProcedureReturn #False
EndIf

Wndows (win32/64):
darkResult=RegReadDWord(#HKEY_CURRENT_USER,"Software\Microsoft\Windows\CurrentVersion\Themes\Personalize","AppsUseLightTheme")
If darkResult=0
ProcedureReturn #True
Else
ProcedureReturn #False
EndIf