I've just been starting down this road. I kind of like orange behind the Class X crime scenes, much more of a distinction between yellow/white, but I haven't decided yet. I *really* like Red behind the Ultimate Challenge which when it lights up gives a good difference between it and the rest of the Chain mode lights. I also just put a really bright 24-led (you won't find this on any of the shops that specialize in pin led's) in place of the planet flasher. I bought it on ebay and when the lightning goes off in the planet, it's pretty awesome. It cost me $1.30 shipped directly from China.