Can dogs see colours? Answer: Yes
Are dogs colour blind? Answer: Yes
Let me explain these two answers to you in a bit more in detail.
Dogs can see colours
Dogs not only see in shades of grey but also can see distinct colours contrary to what most people belief. About one hundred years ago some scientific tests were made to find out more about the colour vision of dogs. But these tests werenÃ¯Â¿Â½t that scientific as they thought and the researchers concluded only that colour vision does not play a part in the daily life of a dog.
Only about 90 years later distinct researches have shown that dogs can perceive colours. Neitz, Geist and Jacobs researched in 1989 the colour vision of domestic dogs and found the following facts:
Dogs have two different colour receptors in their eyes and therefore are dichromate.
One colour receptor peaks at the blue-violet range, the other at the yellow-green range.
Conclusion: Dogs are green-blind which is one form of red-green colour blindness also called deuteranopia.
These results were support by later researches of Jacobs with colleagues in 1993 and Miller and Murphy in 1995.
Dogs are Colour blind
This directly leads us to the second question concerning the colour blindness of dogs. Colour blind does not relate to not see any colours but describes the fact that you cannot see the same colour range as somebody with normal vision. Because of that any kind of colour vision deficiency is called colour blindness. Therefore dogs are colour blind because of their dichromatic colour vision.
Colours dogs cannot distinguish
Actually the colour spectrum made up of wavelengths of light is the same to all of us. Only the perception of those colours can be quite different. As dogs only have two different colour receptors in their eyes they have problems to distinguish certain colours:
Red Orange Green Greenish Blue Grey Different shades of Purple
The list is not completed and there are a lot of different shades which cannot be differentiated if you are colour blind. And the conclusion is dogs can see colours but are at the same time colour blind.