anchor.diff:      (values red green blue)))
   
   (defmethod color-ihs ((color color))
  -  (multiple-value-bind (red green blue) (color-rgb color)
  -    (values intensity hue saturation)))
  +  (multiple-value-bind (r g b) (color-rgb color)
  +    (let ((max (max r g b))
  +	  (min (min r g b))
  +	  (intensity (/ (+ r g b) 3)))
  +      (if (= max min)
  +	  (values intensity 0 0)
  +	  (let* ((saturation (- 1 (/ min intensity)))
  +		 (diff (- max min))
  +		 (hue (* 60 (cond ((= max r) (/ (- g b) diff))
  +				  ((= max g) (+ 2 (/ (- b r) diff)))
  +				  (t (+ 4 (/ (- r g) diff)))))))
  +	    (when (< hue 0)
  +	      (incf hue 360))
  +	    (values intensity hue saturation))))))
   
   (defun make-contrasting-inks (n &optional k)
     (declare (special +contrasting-colors+))
  
positive.code: (defun make-named-color (name red green blue)
    (make-instance 'named-color :name name :red red :green green :blue blue))
  
  (defun make-ihs-color (intensity hue saturation)
    (make-instance 'color :red red :green green :blue blue))
  
  (defun make-gray-color (intensity)
    (make-instance 'color :red intensity :green intensity :blue intensity))
  
negative.code: ;;; -*- Mode: Lisp; Package: CLIM-INTERNALS -*-
  
  ;;;  (c) copyright 1998,1999,2000 by Michael McDonald (mikemac@mikemac.com)
  ;;;  (c) copyright 2000 by Robert Strandh (strandh@labri.u-bordeaux.fr)
  
  ;;; This library is free software; you can redistribute it and/or
  ;;; modify it under the terms of the GNU Library General Public
  