Can Dogs see colors?

The topic whether dogs are color blind may have been long debated but solid research carried out by scientists in the recent years have confirmed the fact that dogs can see beyond black and white; trashing a once popular belief that dogs can only see tinges of gray. The new scientific theory claims that dogs do see colors albeit not as bright or many in number compared to the human visual spectrum.

In fact a  research by Russian scientists confirms that Dogs use visual spectrum to differentiate one color from another and accordingly select objects

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Researchers at the Russian Academy of Sciences from the Laboratory of Sensory Processing carried on an experiment on eight dogs of different breed types. The purpose of sight testing was to conclude that along with having a limited chromatic range dogs can also differentiate between colors and their varying degree of brightness.

Color of toys as seen by dogs. Image;http://pets.stackexchange.com/

The experiment was a step forward to the work done by Scientist Jay Neitz from the University of Washington on the subject. Scientist Neitz found out that dogs have two cones that help them to identify colors blue and yellow, but not red and green. Cones are cells that catch light that enters the eye and help in identifying color wavelengths. Humans have three cones; hence their visual range is complete. For a dog all colors are seen as yellow, blue or gray and their varied shades. Greens or oranges will be seen as yellowish by a dog and violet will be recognized as blue. Even a color blind person has two of the three cones; hence he/she lacks the ability to see all of colors.

The Russian experiment involved the use of four sections of differently colored paper namely dark blue, dark yellow, light blue and light and light yellow. The dark and light shades of the same color were used to prove the theory that a canine can recognize variations in brightness of a certain hue and thereby are able to discriminate between objects.
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The first test entailed using the sheet of papers in a combination of dark yellow and light blue sheets & a dark blue and light yellow combination and these were then placed in front of food bowls that were inside locked boxes.
The second step involved one of the boxes being unlocked and the dark yellow strip of paper was placed in front of the box containing a raw chunk of meat in each testing.

In each testing the dogs were made to try and open a box and then were taken away. It was observed that in just three trials dogs were able to relate the color of paper to the presence of raw meat.

In order to substantiate their findings the researchers wanted to check if the dogs’ selection was based on color or brightness. For this purpose the dark blue and light yellow combination of papers was used. Dark blue piece of paper took its position in front of a box and the light yellow strip was placed in front of the other container.

70% of the times each of the dogs selected the light yellow paper. This proved that their selection was based on the type of color and not brightness (darkness/lightness). Six out of the eight dogs made their pick on the basis of color almost each time. The scientists were able to successfully conclude that for the eight untrained dogs used in the experiment the type of color proved to be more helpful compared to brightness when they were expected to make a certain selection between objects/stimuli varying in the quality of color (chromaticity) and brightness. The testing showed how color information is more important for even an animal containing only two cone photoreceptors that respond to light falling on them.

The colors you see may be different in your dog’s vision. Image:www.ahsaplitjacobi.weebly.com

These findings can help a great deal when it comes to manufacturing dog toys and dog clothing. Colors those are easily recognizable to dogs such as a yellow or a blue must be used in toys. In a game of fetch a toy is flung in the air and the dog is expected to chase and eventually obtain it. A red toy however may merge with the color of the ground and may become difficult for the pooch to locate it as red is seen as dark brown or gray/black by the canine. Dogs can’t discriminate or tell between red and green colors, and hues are categorized on a blue or yellow range.

Article Resources:
https://www.psychologytoday.com/blog/canine-corner/200810/can-dogs-see-colors http://www.dailymail.co.uk/sciencetech/article-2374872/Dogs-CAN-colour-Scientists-dispel-myth-canines-black-white.html