Most hunters in the US wear a blaze orange vest or hat to identify themselves to other hunters. In some states it's codified by law, and in others it's strongly encouraged (in California it's a big part of the mandatory hunter safety course, but is not legally required).
Many big game animals are color-blind (or more specifically, see color differently than we do), so a camo pattern with orange can still hide one from a deer, while making you visible to humans.
For deer (with guns), yes. For things like turkeys, ducks, geese, deer with bows, etc they do not. In hunter safety they really stressed to be careful hunting turkeys.
You seem to be saying that fowl have good color vision, so hunters of those need to avoid the orange stuff, and other hunters can't rely on seeing it to avoid shooting one another.
Deer have more cones and less rods than humans. They have no red-sensitive rods at all. They also have no ultraviolet filtration, so they see blue much more acutely and pick up on UV-wavelength brighteners quite easily.
Many big game animals are color-blind (or more specifically, see color differently than we do), so a camo pattern with orange can still hide one from a deer, while making you visible to humans.