Deer are not totally color blind. That is, they do not see things in black and white. What they do have though is a shift in color perception toward the blue end of the spectrum.



As you can see, a human can detect Blaze Orange very well, but deer have a reduced capability. The still can detect it, just not as well.

Interestingly, clothes washed with regular detergent will reflect blue light very well, so if your choice is to go out with a full suit of Blaze washed in a non-brightener detergent or to go out with a super duper camo suit washed in a regular detergent, then your best bet is to go with the Blaze.

Detergents aside, if you wear Blaze Orange, it's much better to wear a camo orange pattern than solid orange. Still safe for humans, but it breaks up the pattern for deer much better. Also, because deer have excellent blue vision, avoid any clothing with solid blue..

One last thing, deer key in on movement. So wearing a solid Blaze outfit while keeping totally still should be more productive than fidgeting around in your earth tone woodland camo.