lerpHSL method
Implementation
Color lerpHSL(Color color, num alpha) {
getHSL(_hslA);
color.getHSL(_hslB);
var h = MathUtils.lerp(_hslA["h"]!, _hslB["h"]!, alpha).toDouble();
var s = MathUtils.lerp(_hslA["s"]!, _hslB["s"]!, alpha).toDouble();
var l = MathUtils.lerp(_hslA["l"]!, _hslB["l"]!, alpha).toDouble();
setHSL(h, s, l);
return this;
}