brighten method
Brighten the color a given amount, from 0 to 100.
Implementation
Color brighten([int amount = 10]) {
return Color.fromARGB(
alpha,
math.max(0, math.min(255, red - (255 * -(amount / 100)).round())),
math.max(0, math.min(255, green - (255 * -(amount / 100)).round())),
math.max(0, math.min(255, blue - (255 * -(amount / 100)).round())),
);
}