hsl-to-rgb.el

(defun g-hsl-to-rgb (string)
  "Convert a HSL color string (e.g. \"hsl(200, 40%, 80%)\") to an
RGB color string (e.g. \"#e0b7b7\")."
  (when (string-match
         "^hsl( *\\([0-9]+\\) *, *\\([0-9]+\\)% *, *\\([0-9]+\\)% *)$" string)
    (let* ((h (/ (string-to-number (match-string 1 string)) 360.0))
           (s (/ (string-to-number (match-string 2 string)) 100.0))
           (l (/ (string-to-number (match-string 3 string)) 100.0))
           (rgb (color-hsl-to-rgb h s l))
           (r (cl-first rgb))
           (g (cl-second rgb))
           (b (cl-third rgb)))
      (color-rgb-to-hex r g b 2))))