One of very interesting debates on dogs is that the dogs are colour blind. The answer is somehow, confusing as dogs are not human though they love human beings. They cannot tell what they see and are unable to interpret what they observe. Research on whether they are colour blind or not shows mixed results. They are partially colour blind and are partially able to see and distinguish colours. Though the function of eyes and senses is similar to human beings but there are differences of human and non-human. Their vision is dissimilar to humans. They can see better at night whereas humans are less capable of seeing at night.
Dogs are dichromatic
Dogs are able to see only two primary colours: yellow and blue. Cone cells in the eye are responsible for seeing colours. The number of cone cells in dogs is far less than in humans who are trichromatic and can see three primary colours: red, blue, and yellow.
Dogs have 7 times lesser proportion of cone cells than humans
The number of cone cells in dogs is remarkably lesser than in humans. It means that when they see the colors, they find them blurred. Except two primary colors, they cannot distinguish them.
Rod cells in dogs are more concentrated
Rod cells are stronger in dogs and help them concentrate on black and white. That is why their night vision is better than human beings.
Color vision of dogs is a secondary question
The primary role of dogs is to guard, hunt, or protect the life, property, and other belongings of the owner. They have nothing to do with color vision or the reading of primary or secondary colors. They are the best companions, reliable friends, and trustworthy guards. They are not required to read the colors.