hsl2css function
returns an hsl css string like hsl(222, 50%, 75%, 0.6)
from the hsl color and alpha value
Implementation
String hsl2css(num alpha, List<num> hsl) {
var h = hsl[0];
var s = hsl[1];
var l = hsl[2];
var _h = (h * 360).round();
var _s = (s * 100).round();
var _l = (l * 100).round();
return 'hsl($_h, $_s%, $_l%, ${_clampNorm(alpha)})';
}