SassColor.a98Rgb constructor
Creates a color in ColorSpace.a98Rgb.
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.a98Rgb(double? red, double? green, double? blue,
[double? alpha = 1]) =>
SassColor._forSpace(ColorSpace.a98Rgb, red, green, blue, alpha);