Hsla constructor
hue
is a 0..1 fraction of 360 degrees (360 == 0).
saturation
is a 0..1 fraction (100% == 1).
lightness
is a 0..1 fraction (100% == 1).
alpha
is a 0..1 fraction, alpha blending between 0..1, 1 == 100% opaque.
Implementation
Hsla(num hue, num saturation, num lightness, [num? alpha])
: _h = (hue == 1) ? 0 : Color._clamp(hue, 0, 1),
_s = Color._clamp(saturation, 0, 1),
_l = Color._clamp(lightness, 0, 1),
_a = (alpha != null) ? Color._clamp(alpha, 0, 1) : alpha;