I am using the following function to change the colour of the comment delimiter.
Whilst the code works for a dark background, the colour is not changed when using a light background.
(defun delimkl () "Set comment delimiter colour." (if (eq 'dark (frame-parameter nil 'background-mode)) (set-face-attribute 'font-lock-comment-delimiter-face nil :foreground "#00FF00") (set-face-attribute 'font-lock-comment-delimiter-face nil :foreground "#004700") )) 
