As long as your chosen pattern blends in well in the area you are playing the rest is personal preferance. Three things i would recommend however are to firstly, stay away from Black if you are looking to play outdoors, you will stick out like a hooker in church. Secondly, cover your face with cam paint or a balaclava at the very least. Human eyesight is trained to lock onto objects that the brain can recognize, a bare face is one of the easiest thing to pick up.
Thirdly, This is also personal preferance, I would stay away from camo patterned gear and stick with solid, flat colours, ie OD, tan, khaki, etc. Solid colors go well with any BDU you choose, and if you want to change patterns later then at least you won't be stuck with that ACU vest, MARPAT thigh rig and the Tigerstripe BDUs you want. Catch my drift?
Best of luck
Travis R. (aka Trapper)
Canadian Airsoft Marines. Field owner