In this poll, about 77% of A2 owners get white, about 22% get red:
https://www.candlepowerforums.com/threads/135469
I like white, because (even though it doesn't maintain night vision), it's widely useful.
I was surprised how useful the A2's LED "low level" is (in white). Beforehand I pictured it as a special "night use" mode, the incandescent beam being for regular use. In fact the white LEDs have adequate brightness for many daytime tasks, so you need the incandescent beam less often.
Red LEDs would better preserve night vision, but are probably less useful for general daytime utility work than white.
I think the white LEDs have a smoother beam pattern than the other-color LEDs.
That said, if night vision preservation is a key priority, by all means get red. OTOH if you want a dim nightstand light to avoid shocking your mate's eyes, maybe even the red LEDs are too bright. In that case a very dimmable light like an HDS U60, Gladius, or Fire~FlyIII might be better.
The A2 is a great light, but it won't win the "white wall beam pattern beauty contest". As long as that's understood and you focus on the A2's practical utility aspects, you'll probably be satisfied. The A2 is a lot more useful than its specifications would imply.