In co, if you have a tag are in the field you have to wear orange at all times while hunting ( read that as having a firearm on you and a hunting tag- to appease the cpw) even when hunting other species during big game season.
Technically if you are just spotting with no firearm or do not have a hunting tag then you do not have to wear orange-- but be safe, wear it at all times because it's there to protect you from being shot by another hunter. Not everyone should be allowed to hunt. Some seasons overlap ( muzzle loader and archery)-- muzzle loaders must wear orange but archers don't have to, so be extra aware of your surroundings during these times.
People aren't real smart, I see lots of " walkers" during hunting season that don't wear orange ( they probally have no clue its hinting season) I had a walker come within 10 feet of me during turkey season ( no orange required during spring turkey season) before he about crapped his britches seeing a guy in full cammo with a shotgun just 10 feet from him --- he was admiring my decoys (he thought they were real) he had no clue it was hunting season
What I do is go to Walmart and get several of the lightweight cheapo mesh hunting orange vests(mesh is considered legal in CO) -- I wear one at all times when not in camp, and one goes over my pack too... if I get an animal, when I carry it out (especially with the head) I put another mesh vest on any visible parts of the animal that another hunter might see... also if I have to leave parts in the field whe packing out meat, I toss one on it too ( it kind of shows possession to keep other hunters away from my meat)
As far as hats, if it's hot, it's an orange ball cap-- cold, it's An orange beanie