brighten method
Brightens the color with the given integer percentage amount. Defaults to 10%.
Implementation
Color brighten([final int amount = 10]) {
if (amount <= 0) return this;
if (amount > 100) return Colors.white;
final Color color = Color.fromARGB(
alpha8bit,
math.max(0, math.min(255, red8bit - (255 * -(amount / 100)).round())),
math.max(0, math.min(255, green8bit - (255 * -(amount / 100)).round())),
math.max(0, math.min(255, blue8bit - (255 * -(amount / 100)).round())),
);
return color;
}