Desperado, I took the same test, and am like 80% color deficient. It SEVERELY limited my jobs in the Army-but, I went in to be a grunt, and they didnt have an issue with that (is that discrimination?!?!?!). I never once had an issue reading maps with a red light-using night vision gear either, which I was also told wouldnt work (no idea what they based that on!!!).

The thing that gives someone away, more than ANYTHING else, is movement. As has been stated above. Even well trained individuals can give themselve away by lack of it-when the wind blows, almost everything moves-except rocks and people. If you are observing an area for a while, you sort of catalog everything in your FOV. When the wind blows strong enough, you can sometimes pick out silhouettes-even if someone is using some sort of screen. Granted, this isnt something that people look for unless its their job...but usually movement, or unnatural LACK of movement, give away a person. Muted colors normally blend in, particularly at a distance. They human eye is easily tricked...but some things you simply cant replicate.