Funny you ask - I just put a red multi LED in mine (19 LED's I think). I used red because that's what they use on warships/subs etc so your eyes don't have to re-adjust to darkness after seeing white light. Also replaced anchor and cabin lights to reduce power consumption. They make all kinds of replacements for regular 12V bulbs.
http://www.superbrightleds.com/led_prods.htm