This code establishes two groups of nicks for rcirc – pals and bots. Pals’ nicks are green, bots’ nicks are red. Your nick is blue and everyone else’s nicks are yellow.
;; This code is by Trent Buck <trentbuck@gmail.com>
;; It is in the Public Domain.
(setq rcirc-bots '("fsbot" "birny" "lisppaste" "specbot"))
(setq rcirc-pals '("rcy" "sabetts" "bkhl" "twb"))
(defface rcirc-pal-nick-face
'((((class color) (background dark)) :foreground "PaleGreen")
(((class color) (background light)) :foreground "PaleGreen3"))
"Face used for nicks in `rcirc-pals' list.")
(defface rcirc-bot-nick-face
'((((class color) (background dark)) :foreground "tomato")
(((class color) (background light)) :foreground "tomato3"))
"Face used for nicks in `rcirc-bots' list.")
(defadvice rcirc-facify (before rcirc-facify-pals)
(when (eq face 'rcirc-other-nick)
(when (member string rcirc-pals)
(setq face 'rcirc-pal-nick-face))
(when (member string rcirc-bots)
(setq face 'rcirc-bot-nick-face))))
(ad-activate 'rcirc-facify)