Why are chickens afraid of red?

Roosters are not afraid of red, but they will feel safe when they see something red.

There used to be this thing. It is said that in a chicken farm in the United States, in order to prevent roosters in estrus from pecking at each other, the owner put on red contact lenses for each rooster.

Chickens are color blind, right? They shouldn't see color, but I don't know if they can see red. If you can see it, you may know that it is the color of blood, because you are afraid of death. The chicken naturally won't give it to you!

So chickens are not afraid of red.