color-alpha

Returns the alpha component of a color specification.

color

color-alpha color-spec &optional default => alpha

`color-spec`⇩	A color specification.
`default`⇩	A number between 0 and 1.

alpha

The alpha component of color-spec.

The function color-alpha returns the alpha component on color-spec, which is a color specification in any model.

If color-spec does not have an alpha component, then default is returned.

The default value of default is 1.0.