Camo varies a lot. Best thing to do is to use a piece of actual camo as inspiration.
Camo tends to be dull colors, not brights. Sometimes black, sometimes just very dark tones. So greens in the avocado and olive families -- not primary and bright. Same thing with the desert sands. There is also winter and other specialty camos.
My dad was in the Army and when I think camo it is 1960s military grade and not modern hunting.