Contrary to popular opinion, no they are not, it is just that the number of colors they can distinguish between is more limited than what other animals and humans can discern.

In the eye, the cone cells in the retina are what recognize color and dogs have fewer of them than humans, but they do have some. According to scientists, this means that the colors that they do see would seem faded or ‘washed out” to human eyes so they are not good at picking up all the different shades of the basic colors around them. Dogs, say researchers, have dichromatic vision, meaning that they can pick up only two primary colors – blue and yellow, while a human’s trichromatic vision can discern red as well.

Where scientists say dogs do score over humans is that while they lack cone cells, their eyes contain more rod cells, making their black and white vision far more accurate as well as their vision in low light (their night vision).

Still, since there are no dog scientists (or at least no ones that can talk) many people still feel this is all speculation and will swear that their dog can recognize a red or pink blanket or toy over a green or yellow one. This is probably more likely to be related to a personal preference for the texture or size of the blanket than its color.