Strange But True: Reddish colors prove challenging for dogs

Q. When people go out to buy their dog a toy, what mistake do they commonly make?

A. They purchase popular toy colors like red or safety orange (the bright orange red of traffic cones or safety vests) that are difficult for dogs to see, says psychologist Stanley Coren in “Do Dogs Dream? Nearly Everything Your Dog Wants You to Know.” Tests show dogs have trouble seeing red, which can appear to them as dark brownish gray or even black. Not that dogs are color blind, as many people believe, but they are “color-challenged.” We humans have three different kinds of light-catching cones affording us our full range of color vision. Dogs have only two.

University of California, Santa Barbara, researcher Jay Neitz tested dogs by showing them a set of three light panels — two of the same color, the third different. Only if the canines picked out the lone color did they get a treat. Thus Neitz confirmed that dogs do see colors but many fewer than normal humans do. Instead of seeing a rainbow of colors, “dogs see the world as basically yellow, blue and gray.”

So, Coren says, that bright red toy so visible to you may not be what your dog sees. “If your own pet version of Lassie runs right past the toy you tossed, she may not be stubborn or stupid. It may be your fault for choosing a toy with a color that is hard to discriminate from the green, grass of your lawn.”