Are Pigs Color Blind?

Humans have trichromatic vision, meaning that three pigment cones blend together to create the colors people see. Pigs and other mammals have dichromatic vision, or only two pigment cones that create colors. This means a pig's view of the world is less rich than a person's, but that a pig can still differentiate colors. Animals with monochromatic vision have only one pigment cone and see in black and white.

Pigvision Institute studies showed that pigs see primarily red, green and blue wavelengths. When these colors are combined -- for example, in a multicolored pig food with red, green and blue pellets -- pigs will display a stronger visual response than when facing one color. Additionally, pigs tend to see objects as solid color; they may see the blue sky, but not perceive clouds or rainbows in the sky.

For a long time, researchers thought that all mammals -- including pigs -- were color blind, a belief that was common knowledge among the general public. Accordingly, some folks may still believe pigs lack the capacity to differentiate colors. While recent research has shown that pigs and other mammals are not truly color blind, this is less well-known to the general population.

By playing to the color perception of pigs, farmers, pig breeders and pig owners can make pigs more comfortable and less stressed in their environment. For example, the pig will see a farmer wearing red, green or blue pants and boots better than a farmer wearing brown pants and boots. When the element of surprise is removed -- the pig sees the farmer approach -- the pig may be less anxious.