Deer hunting clothing is big business, what they can and can't see has been studied to death. The different colors are due to the wavelength of light, the blue end of the spectrum are short and the red end are long wavelengths. Deer can see the blue end better than we can, don't wear blue jeans when hunting. But the other end like red or orange is just grey. Green is seen pretty much as a grey, at least it won't stand out, especially when in camouflage. Green camouflage is a good color for deer hunting and other game hunting. Green/tan camo is probably so popular because it works for so many different animals.
Hunter orange is not common in nature and humans can see it really well. It really stands out to people so it has saved a lot of lives without alerting deer. So you buy basic camo for all hunting and add and orange vest or cap for deer. Different states have different requirements for how much orange.