(defun list-hexadecimal-colors-display ()
  "16進数で色一覧を表示"
  (interactive)
  (let ((r 0)
        (g 0)
        (b 0)
        (delta 32)
        (color-list ()))
    (while (< r 256)
      (setq g 0)
      (while (< g 256)
        (setq b 0)
        (while (< b 256)
          (setq color-list (append color-list (list (format "#%.2x%.2x%.2x" r g b))))
          (setq b (+ b delta)))
        (setq g (+ g delta)))
      (setq r (+ r delta)))
    (list-colors-display color-list)))