It looks fucking cool. Here is an example from another game.
Olive Drab is already in the game as a color for equipment, but not the uniform itself. That could possibly mean that the devs didn't include it because it might be too dark? Mikee said something like that about black camouflage on a stream. Anyway, I think it would be neat.
Suggestion: Olive Drab as Uniform Camo
So far, solid colored clothing has been exclusively reserved for the Insurgent side. I know they're concerned with keeping teams easily identifiable by uniform, especially now in Hardcore with no friendly HUD markers.