when is camo vital

[cpd realpolice]

Ok here comes a dumb question by a new hunter, but it's always been something I've wondered. What animals is it vital to wear camouflage. The reason I ask is that I watch numerous tv shows where the hunter is camo'd up from head to toe with $100's of dollars in camo and the guide is wearing a pair of wranglers, a flannel and a cap. So which animals is camo vital and which animals is it not. Thanks, I got that question out of my system.