I think a member on this forum (I can't remember who right now) can take a picture of a ride and fill in the colors of what you might think you want to change/paint. By modeling first, you should get a pretty good idea of what the changes will look like. Unfortunately, I am not that good with a computer, so I don't know exactly how to do. But if you can or know someone, it may be worth the time to do that first.