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 = ColorFilter((Color inputColor, [List<num> args = const []]) {
var color = inputColor.toCielabColor();
num rgbLevel = color.l * 255 / 100;
return RgbColor(rgbLevel, rgbLevel, rgbLevel).toCielabColor();
}, CielabColor);