Experimental evidence
Misconception about the absence of color vision of these animals has been refuted by American scientists. Several sealed boxes marked with paper sheets of different colors were taken. Some food was put in each box. Raw meat - a favorite dog's treat - was under a sheet of dark yellow color.
The aim of the experiment was to allow dogs to correlate a particular color with the contents of the box, in other words, the animals must have understood the meat was in the box with the sheet of dark yellow paper. The results were impressive. Dogs easily coped with the task - they faultlessly found out the meat, focusing only on the corresponding color of the leaves, as the tightness of the box didn't let them to smell the meat.
Dogs’ perception of colors pecularities
Dog's eye is quite similar in structure to the human eye. The only difference is in the variety and ratio of so-called cones and rods. Cones are a type of specific photoperceptors, which are located on the retina. Humans have three types of cones and each of them perceive their own color range: some react on red and orange colors, second - on yellow and green, and the third - on dark blue, purple and blue. Dogs don't have cones that are sensitive to red color. Therefore, their vision can be compared with vision of colorblind person.
But because the dogs have much more photoperceptors on the retina, so called rods, the animals are able to distinguish up to 50 shades of gray, inaccessible to the human eye. It should be also noted that dogs have much more sensitive rods if to compare them with the same receptors of the human eye. All this makes animals able to see in the dark almost 4 times better than any human.
Thus, to summarize the above, dogs can appreciate blue and yellow colors, but their intensity of perception is much lower in comparison with people. Green and red color the animals see as yellow-gray and mix them up. Therefore, guide dogs, for example, are taught to distinguish the traffic lights not by the colors but by their location and sequence of light .
Having an understanding of dog's color vision it could be much easier to train them. To do this, use blue or yellow shells and trainers, then the dog is able to easily appreciate them among gray shades. Also, while buying toys for your pet, it is important to follow its preferred colors. The dog will much like yellow and blue toys than red-green ones.
