mix method
Implementation
Color mix(Color toColor, [int amount = 50]) {
final p = RangeError.checkValueInInterval(amount, 0, 100, 'amount') / 100;
return Color.fromARGB(
((toColor.alpha - alpha) * p + alpha).round(),
((toColor.red - red) * p + red).round(),
((toColor.green - green) * p + green).round(),
((toColor.blue - blue) * p + blue).round(),
);
}