greyscale property
Creates a greyscale color with the same perceived luminance as the source color (as given by the L* value of the color in the CieLAB color space).
Implementation
static ColorFilter greyscale = new ColorFilter((Color inputColor, [List? args]) {
CielabColor color = inputColor.toCielabColor();
num rgbLevel = color.l * 255 / 100;
return new RgbColor(rgbLevel, rgbLevel, rgbLevel).toCielabColor();
}, CielabColor);