src/vs/platform/theme/electron-main/themeMainService.ts/ThemeMainService/getColorScheme
class ThemeMainService:	getColorScheme(): IColorScheme {
		if (isWindows) {
			// high contrast is refelected by the shouldUseInvertedColorScheme property
			if (nativeTheme.shouldUseHighContrastColors) {
				// shouldUseInvertedColorScheme is dark, !shouldUseInvertedColorScheme is light
				return { dark: nativeTheme.shouldUseInvertedColorScheme, highContrast: true };
			}
		} else if (isMacintosh) {
			// high contrast is set if one of shouldUseInvertedColorScheme or shouldUseHighContrastColors is set, reflecting the 'Invert colours' and `Increase contrast` settings in MacOS
			if (nativeTheme.shouldUseInvertedColorScheme || nativeTheme.shouldUseHighContrastColors) {
				return { dark: nativeTheme.shouldUseDarkColors, highContrast: true };
			}
		} else if (isLinux) {
			// ubuntu gnome seems to have 3 states, light dark and high contrast
			if (nativeTheme.shouldUseHighContrastColors) {
				return { dark: true, highContrast: true };
			}
		}
		return {
			dark: nativeTheme.shouldUseDarkColors,
			highContrast: false
		};
	}