anchor.diff:  	  (setq left right right (+ right increment))
   	  (incf intensity quantum))))))
   
  -#-clim-2
  -(define-presentation-type color-presentation ()
  -  :description "a color"
  -  :parser ((stream)
  -	   (completing-from-suggestions (stream)
  -					(dolist (color *colors*)
  -					  (suggest (first color) (third color)))))
  -  :printer ((object stream)
  -	    ;; Present the textual name, rather than a swatch of color.
  -	    (write-string (string object) stream))
  -  :accept-values-displayer
  -  ((stream object query-identifier)
  -   (accept-values-choose-from-sequence
  -    stream *colors* object query-identifier
  -    :drawer
  -    #'(lambda (stream object name selected-p)
  -	(draw-color-swatch stream object name selected-p)))))
  -
  -#+clim-2
   (clim:define-presentation-type-abbreviation color-presentation ()
     ;; Can't simply call this 'color' because that already names a class.
     `((member ,@(mapcar #'third *colors*))
  
positive.code:     :printer present-color
      :highlighter highlight-color))
  
  #+clim-2
  (defun present-color (object stream &key acceptably)
    (declare (ignore acceptably))
    (with-room-for-graphics (stream)
  
negative.code: 	     (setf (gethash name colors) (make-color-rgb red green blue))
  	     (pushnew (list (string-capitalize name) :value name)
  		      *colors*
  		      :test #'equal))))))
  
  (defun initialize-color-system ()
    "Initialize the color screen if available."
    ;; Called by ALU-FOR-COLOR the first time an alu is needed.
    (make-color-choices *color-specifications*))
  
  (defun alu-for-stream (stream color-name)
    "Translate a color name to an ink/alu"
    (if (color-stream-p stream)
        (alu-for-color color-name)
        (if (eq color-name :black) %erase %draw)))
  
  (defun draw-color-swatch (stream color-name pretty-name selected-p &optional size)
    "Draw a sample of the given color at the current cursor position."
  