Please enlighten us then.
It may seem obvious, but it's actually pretty rare that people know how to use camouflage.
The people I play with like to stay upright at ALL times, but that has more to do with hiding behind cover than using camo. (Though woodland looks more like the GROUND of the woodlands rather than the sky above it)
When using camouflage, you need to look like the surroundings you're
in, not that you're
near. There's a field I play at that's half in the woods, while the other half is on a grassy hill (yellow grass most the time). And there's a base that's surrounded by grey stones, perfect for
UCP. Having a type of camo doesn't work EVERYWHERE in a field.
Most airsofters can see camouflage if they know which way to look, if they're expecting you, whether you're moving or not. If you're coming from a direction they don't expect however, sometimes even the worst camo can work out great. I've seen a guy get within 20ft of a target in a woodland area using UCP.
To simplify, camouflage
enhances stealth, it doesn't
cause it. If you're not being stealthy to begin with, it doesn't matter what kind of camo you're wearing, the enemy will notice you.