result))
(nreverse result)))
+(defun color-hue-to-rgb (v1 v2 h)
+ "Compute hue from V1 and V2 H. Internally used by
+`color-hsl-to-rgb'."
+ (cond
+ ((< h (/ 1.0 6)) (+ v1 (* (- v2 v1) h 6.0)))
+ ((< h 0.5) v2)
+ ((< h (/ 2.0 3)) (+ v1 (* (- v2 v1) (- (/ 2.0 3) h) 6.0)))
+ (t v1)))
+
+(defun color-hsl-to-rgb (H S L)
+ "Convert H S L (HUE, SATURATION, LUMINANCE) , where HUE is in
+radians and both SATURATION and LUMINANCE are between 0.0 and
+1.0, inclusive to their RGB representation.
+
+Return a list (RED, GREEN, BLUE) which each be numbers between
+0.0 and 1.0, inclusive."
+
+ (if (= S 0.0)
+ (list L L L)
+ (let* ((m2 (if (<= L 0.5)
+ (* L (+ 1.0 S))
+ (- (+ L S) (* L S))))
+ (m1 (- (* 2.0 L) m2)))
+ (list
+ (color-hue-to-rgb m1 m2 (+ H (/ 1.0 3)))
+ (color-hue-to-rgb m1 m2 H)
+ (color-hue-to-rgb m1 m2 (- H (/ 1.0 3)))))))
+
(defun color-complement-hex (color)
"Return the color that is the complement of COLOR, in hexadecimal format."
(apply 'color-rgb-to-hex (color-complement color)))