I was asked recently if dogs can see color. The reason for the question was an interesting story in itself. The lady’s dog is a very sweet pit bull mix. Recently they were on a walk and saw a small breed dog that had been died yellow (yes – YELLOW). Apparently, her pit bull stopped, cocked her head to the side and stared. I can imagine her thinking “What will they think of next?”
But was it the color she was reacting to or the something else? Can dogs see color? Turns out they can. Scientist Jay Neitz from the University of Washington, carried out experiments on dogs to test whether they could see colors. Human eyes have three 'cones' that detect color and can identify red, blue, green and yellow. Neitz discovered that dogs only have two cones - this means they can distinguish blue and yellow, but not red and green. This is the same spectrum seen by humans when they have color blindness.
Russian researchers wanted to test the theory that dogs use brightness more than color. They used four pieces of paper in different colors. Researchers took a dark yellow and light blue sheet of paper, as well as a dark blue and light yellow combination and put them in front of food bowls placed inside boxes. They unlocked one of the boxes and put the dark yellow piece of paper in front of the box containing a piece of raw meat in each trial. Each test involved the dogs being allowed to try to open one box before being taken away. It only took three trials for the dogs to learn which color paper was sat in front of the box containing the raw meat.
Once the dogs could identify that a piece of dark yellow paper meant meat was nearby, the researchers wanted to check whether the animals were choosing this paper because of its brightness or its color. To do this they put the dark blue paper in front of one box and light yellow in front of another. If the dogs chose the dark blue paper, the scientists could rule that the animals were making choices based on brightness. However, if they chose the light yellow paper, the choices were based on color. Each dog chose the light yellow paper - meaning they were making choices based on color - more than 70 % of the time. Six out of the eight dogs made the color choice between 90 and 100 per cent of the time.
In conclusion, the researchers said: 'We show that for eight previously untrained dogs color proved to be more informative than brightness when choosing between visual stimuli differing both in brightness and chromaticity.