chickadee » web-colors » *web-color-names*

Contains a list of (symbol . list) pairs for named colors. You can override this parameter to change the color names recognized by parse-web-color, parse-named-color, and web-color-name. Color names should contain only lower-case letters, numbers, and hyphens.

;; Add the colors "amaranth" and "viridian".
(*web-color-names*
 `((amaranth . (rgb 229 43 80 1))
   (viridian . (rgb 64 130 109 1))
   ,@(*web-color-names*)))

(parse-web-color "amaranth")
; → (rgb 229 43 80 1)

(web-color-name '(rgb 64 130 109 1))
; → "viridian"