Deer see some colors, it is not ultra violet rays. If you are in laurel with snow and wearing camo orange, deer are pretty much blind to it. Sit in a snow bank with solid orange and you are good. Wear camo or solid orange and sit in front of a hemlock tree and an experienced deer will pick you out. An experienced deer will pick out orange on foggy, overcast days. Remember when biologists told you deer only see in black and white? Early in the morning when it is just getting light the woods looks like an old black & white TV. Everything looks black and grey and white to you EXCEPT blaze orange. You can pick that right out. So now biologists say they "Discovered" that deer see some colors. This is the same group of people that told you for years they could only see black and white.