Weird Cammo Suit

I've been playing sniper in MW3 with the cromatix. I've set snipers as flashygreen, but only a small amount, like 5% look fullblack instead of flashygreen

I thought it could be a different cammo suit for those who do some sort of "challenge" in the MW3 game or that they might have a custom class with speficific stuff.

Does anyone have any idea about this?