I'm in the midst of doing this myself. I've put the little red condoms over the dome and reading lamp, and was going to put in red lights for the AC, hazard light switch, etc but I took one of the buttons out and found that there is a green light bulb, but also a green tint to the plastic. One would have to replace the plastic in some way to get it to shine any color than green. Well, it could be red, but with a green tint to it :barf:
A friend of mine told me that she could probably make some molds and do the buttons in a clear plastic, but that is not a priority of mine at this point, so I've not gone any further with it.
This is all considering I'm a gen2, but I would assume it the same for all of them.