darken static method
Adjust a color and make it darker.
Implementation
static Color darken(Color color, [double amount = .1]) {
assert(amount >= 0 && amount <= 1, 'Needs to be in range');
final hsl = HSLColor.fromColor(color);
final hslDark = hsl.withLightness((hsl.lightness - amount).clamp(0.0, 1.0));
return hslDark.toColor();
}