SassColor.oklab constructor
Creates a color in ColorSpace.oklab.
If null is passed for alpha, that indicates that it's a missing
component. In most cases, this is equivalent to the color being
transparent.
Throws a RangeError if alpha isn't between 0 and 1.
Implementation
factory SassColor.oklab(double? lightness, double? a, double? b,
[double? alpha = 1]) =>
SassColor._forSpace(ColorSpace.oklab, lightness, a, b, alpha);