color-darken-hsl

color-darken-hsl is a compiled Lisp function in `color.el'.

(color-darken-hsl H S L PERCENT)

Make a color darker by a specified amount.
Given a color defined in terms of hue, saturation, and luminance
(arguments H, S, and L), return a color that is PERCENT darker.
Returns a list (HUE SATURATION LUMINANCE).