brighten method

Color brighten([
  1. int amount = 10
])

Implementation

Color brighten([int amount = 10]) {
  final p = RangeError.checkValueInInterval(amount, 0, 100, 'amount') / 100;

  return Color.fromARGB(
    alpha,
    math.max(0, math.min(255, red - (255 * -p).round())),
    math.max(0, math.min(255, green - (255 * -p).round())),
    math.max(0, math.min(255, blue - (255 * -p).round())),
  );
}