We all grow up being told that dogs cannot see color. Is it true? Should we believe everything we are told? Let's learn together and see.

To understand best, let's review a very basic summary of how vision works.

When light enters your eye, it passes through the cornea, aqueous humor, lens
and vitreous humor. It's ultimate destination is your retina.
The retina is the light sensing structure of the eye The retina contains two types of cells, the rods and cones.
Rods handle vision in low light, cones hand color vision and detail. Cones are the one we are interested in (if we want to learn the answer to our ultimate question).

Humans have three cones which contain color-responsive chemicals (cone pigments). The three kinds of cone pigments are red-sensitive, green sensitive and blue sensitive.
Each cone contains one of these pigments so that humans can see almost any gradation of color.

Color blindness in humans occurs when one of the cones (either red or green) are missing or are not functioning properly. Called red-green colorblindness.

Why this is important?
Dogs only have two cones (humans have three), so a dog's ability to see is comparable to a human with red-green colorblindness.

The answer then? I must conclude that while dogs see more than just black, white or grey, in a technical sense, dogs are colorblind.

credit to: Mark Plonsky, PhD
How Vision Works by Carl Bianco, MD

Again, this credit goes to Mark Plonsky PhD. In his article he gives his estimate of the color range your dog probably sees.