I am guessing but you probably don't need resistors because the voltage has already been stepped down. I am planning to do that within the next couple of weeks. I have already changed the lights in the gauge pod to blue. I did not go the LED route though. I removed the stock plastic thingies that give the lights their color and replaced it with blue plastic that I cut out from a report folder. You can find all the details at my web page at:

http://home.att.net/~ivanypatty/