I've thought of this too. But I don't think any of the carts nor the box identify what format they are in. As for the combat colours, they are black and white even though I have the atari on colour tv mode, but that could be because the tv itself has its colours turned down for whatever reason or because the tv can't adjust. It would display flashes of red, at least for one of them. I'll check the tv settings I guess.
EDIT: I was wrong. It was switched to black and white. On colour, the tv was adjusting and displayed a green battlefield, I think, and then went back to exploding.
EDITEDIT:
http://i.imgur.com/KlmVwE3.jpg Stupid glitched driver webcam taking pictures way too large even though I probably have it on the highest setting but whatever.
Anyways, that's Combat on 15 - Biplane. When I was testing before, it was switching to black and white and back. Now, it was able to stay on this screen for a while. It was also scrolling down-right or something. I guess I could always see if there are repairs to be made to the 2600 as well?