I have one with white LEDs. Personally, I don't see the need for any other colors, even red. But if you want others, you can get Aviatrix rings in enough colors to have a different one for every day of the week. But when in doubt, go for white LEDs, as it's the most general purpose color.
I mostly use mine for walking the dog. The LEDs are sufficiently bright to see where I'm putting my feet and their wide and non-hotspotty beam pattern is ideal for this purpose, too. Every now and then I scan the path ahead with the incan beam to see if there are other people, dogs, or bicycles approaching us. The A2 is a great light for this kind of activity.