I have a green plate carrier with tan pouches to break up my silhouette some. I've run this successfully with a couple of sets of camo (namely Flecktarn and Multicam). With a black T-shirt and Multicam pants on, I've "disappeared" while standing up and shooting at the people looking for me.
Lemme see if I can dig up a photo:
Poor lighting, but that's something like what it looks like with the Multicam top on. Ignore the other stuff I have on; most of it's been replaced with nicer equipment.
Vest as it sits when I'm not wearing it.