I have two A2s, one red and one yellow-green. The reason I don't have white is because I have other two-stage white lights that are LEDs. For me the unique thing about the A2 is being able to have two colors.
Pretty much however you cut it, the LED mode on the A2 is for close-up work, like reading or filling out forms. Color rendition definitely can be a problem with red on things like maps. The yellow-green works surprisingly well, since the spectrum is quite broad for a single-color LED. You actually can make out blues and reds just a little bit, and of course colors in between are much better.
I have found it to be true that red is a better color for seeing through smoke and haze. I have an Aleph 3 with a red-orange Luxeon III that does a great job. But there is a catch: the strange thing about red is that, as it gets less intense, your ability to see it diminishes disproportionately. Both my A2s are about the same brightness close up (in fact the red is a lot brighter for reading). But at around 20 feet, the red light just about vanishes. I see the same thing in the Aleph at around 75 yards. The yellow-green acts like a normal light.
The red A2 is great for stargazing and poking around the house without waking anyone. It is my "bump in the night" light for this reason. It is wonderful when a low-observable low mode and a good throwing high mode is what you are after.
The yellow-green is decent at preserving night vision, still a very soft light. It is a very pleasant light to read by. The notable feature is that you can still make out other colors reasonably well.
The green and blue just don't do much for me. Cyan would be cool though.
Scott