I took that thing apart a couple of times. The bulbs are regular yellow bulbs covered with blue or green covers. Yellow with green cover give you the same faded green colour as yellow with blue cover. If you take of the covers, tou will get indigo (orange) colour similar to that you get in BMW's. I had no multimeter to measure what kind of resistor I need to install leds. I needed indogo to match my deck anyway.
It is pretty simple guys...just don't scratch anything.