Mirek,

I thought I could apply custom colors through SColor*_Write(), so I tried this for UWord dropping the following code into the place where default SColors are initilized in ChWin32.cpp:

...
	for(sysColor *s = sSysColor; s < sSysColor + __countof(sSysColor); s++) // this also resets all imls via SColorPaper_Write!!!
		(*s->set)(sAdjust(Color::FromCR(GetSysColor(s->syscolor))));

	SColorDisabled_Write(Color(0x95, 0x95, 0x95));
	SColorDkShadow_Write(Color(0x20, 0x20, 0x20));
	SColorFace_Write(Color(0x20, 0x20, 0x20));
	SColorHighlight_Write(Color(GetSystemAccentColor()));
	SColorHighlightText_Write(IsDark(SColorHighlight())?White():Black());
	SColorInfo_Write(Color(0x20, 0x20, 0x20));
	SColorInfoText_Write(White());
	SColorLabel_Write(Color(0x20, 0x20, 0x20)); // White());
	SColorLight_Write(Color(0x20, 0x20, 0x20));
	SColorLtFace_Write(Color(0x20, 0x20, 0x20));
	SColorMark_Write(Color::FromCR(GetSysColor(COLOR_HOTLIGHT)));
	SColorMenu_Write(Color(0x20, 0x20, 0x20));
	SColorMenuMark_Write(Color::FromCR(GetSysColor(COLOR_HOTLIGHT)));
	SColorMenuText_Write(White());
	SColorPaper_Write(Color(0x19, 0x19, 0x19));
	SColorShadow_Write(Color(0x20, 0x20, 0x20));
	SColorText_Write(White());

having first implemented this:

RGBA GetSystemAccentColor(){
	RGBA	color=Gray(); // Default
	
#ifdef WIN32
    HKEY	SWKey;
    HKEY	MSKey;
    HKEY	WINKey;
    HKEY	DWMKey;
    
    LONG	Status;
	
	// "Computer\HKEY_CURRENT_USER\Software\Microsoft\Windows\DWM"

    Status = RegOpenKeyEx(HKEY_CURRENT_USER,TEXT("Software"),0,KEY_READ,&SWKey);
    if(Status == ERROR_SUCCESS){
		Status = RegOpenKeyEx(SWKey,TEXT("Microsoft"),0,KEY_READ,&MSKey);
	    if(Status == ERROR_SUCCESS){
			Status = RegOpenKeyEx(MSKey,TEXT("Windows"),0,KEY_READ,&WINKey);
			if(Status == ERROR_SUCCESS){
				Status = RegOpenKeyEx(WINKey,TEXT("DWM"),0,KEY_READ,&DWMKey);
				if(Status == ERROR_SUCCESS){
				    DWORD RegType=REG_DWORD;
				    DWORD BufferSize=4;
				    byte pStr[16];
					
			        Status=RegQueryValueEx(DWMKey,TEXT("AccentColor"),NULL,&RegType,(LPBYTE)pStr,&BufferSize);
			        
			        if(Status == ERROR_SUCCESS){
			            color.a=pStr[3];	// This is ARGB
			            color.b=pStr[2];
			            color.g=pStr[1];
			            color.r=pStr[0];
			        }
			        
					RegCloseKey(DWMKey);
				}
				RegCloseKey(WINKey);
			}
			RegCloseKey(MSKey);
	    }
	    RegCloseKey(SWKey);
    }
    if(Status == ERROR_SUCCESS) return color; // Success
    
#endif
	// TODO solve other sources
	
	return color; // Default
}

Some parts of the GUI follow these colors, but many don't. So, the results are mixed with partly unreadable GUI. While the suggested colors are definitely not optimized, could you try the above with both light and dark theme in Windows? I could use some help here in order to get onto the right track in tuning the default theme. UWord seems to be a good place to test as it has many different Ctrls in e.g. Style manager.

Best regards,

Tom

	if(sEmulateDarkTheme) {
		SColorPaper_Write(Color(...));
		SColorFace_Write(Color(...));
		SColorText_Write(Color(...));
		SColorHighlight_Write(Color(...));
		SColorHighlightText_Write(Color(...));
		SColorMenu_Write(Color(...));
	}
	else
		for(sysColor *s = sSysColor; s < sSysColor + __countof(sSysColor); s++) // this also resets all imls via SColorPaper_Write!!!
			(*s->set)(sAdjust(Color::FromCR(GetSysColor(s->syscolor))));