Dog research has dispelled the myth once and for all that dogs only see in black and white. The study has proved that dogs see in various colors.
An experiment in Russia on eight dog breeds has proved that dogs look at the world in blue, yellow and many shades in between.
For a long time scientists have known that dogs could see in a variety of colours, but it was thought that they used levels of brightness, and not color per se, to distinguish different objects.
Recent research found that dogs have two types of cones in their eyes. This led scientists at the Institute for Information Transmission Problems of the Russia Academy of Sciences to suspect they could distinguish colors.
Humans, on the other hand, have three kinds of cones. This allows us to see all three primary colors.
With only two cones, dogs should be able to see some colors, but not others. The researchers suspected dogs would for example be able to see shades of blue, green and yellow, but not red and orange. The experiment was designed an experiment to test this theory.
First they trained several dogs to respond to one of four pieces of paper of different colors: light yellow, dark yellow, light blue and dark blue. The sheets of paper were placed in pairs in front of feed boxes containing meat.
The dogs soon learned that certain colors meant a treat.
Next, the researchers placed pieces of paper with the color the dogs had been taught to respond to in front of a feed box, along with another piece of paper that was brighter, but of a different color, to see if a dog trained to respond to light blue would respond to dark blue instead of light yellow.
A majority of the dogs went for the color identifier rather than brightness identifier. The the scientists said this proves they are able to distinguish color and were not relying on brightness to find their food treat.
Three-quarters of dogs selected the right colour more than 90 % of the time.