darker method

Color darker(
  1. double percent
)

Make a darker color by subtracting percent of 255 from its red|green|blue value.

Implementation

Color darker(double percent) {
  var v = -percent * 255.0;
  return Color.fromRGBO(_clampColorValue(red + v),
      _clampColorValue(green + v), _clampColorValue(blue + v), opacity);
}