I've done a bit of work with LED's in the past as well, and for your application I would definately recommend "white" LED's. The way they make white LED's is by taking a blue LED and then applying a phosphorescent coating to the inside of the lens that absorbs the blue light from the LED and re-emits it as white light. Therefore, LED's that are sold as "white" often have a blue tinge to them since not all of the blue light is absorbed by the coating, a small amount seeps through.
This is also why many of the white LED's that you will find are rated as much less bright than other colors. The absorbtion and re-emission isn't 100% efficient, some of the enegy is lost. Of course you can just compensate by using more LED's... This is also why white LED's are so much more expensive than other colors, the manufactuing process is much more involved.
The one downside that I've noticed to white LED's is that they are not all exactly the same color. I'm assuming this is due to the fact that the coating cannot be applied exactly the same to each LED and manufactuing inconsistencies cause different shades of "white". Of course, this was 4 or 5 years ago that I was playing with these, only a few months after they were invented and they might have fixed this problem since then.
One other suggestion. They sell LED's with the resistors built in. They're a bit more expensive, but they save you a lot of time and the packaging would take up less space. If you're concerned about "covering up" the inner workings, this might be a good idea.
Also, let me comment that LED's that are listed as red/green or red/green/blue are not infinately adjustable in their color. They can switch between colors, but you can't for example get purple out of a red/green/blue LED. Of course if you had two red/green/blue LED's next to each other and one was on red and the other was on blue, the resulting color would appear to be purple (this is how TV screens work).
Good luck with this project! I didn't know what angel eyes were before I started reading this thread, they look sweet! I'm getting all inspired to go and try to put a set of my own together...
Has anyone experimented with different colors? Say yellow? You'd get pulled over for using red, but yellow shouldn't be a problem. I'm just wondering if anyone has seen different colors used and if it looks good.