How Does Man’s best Friend View the World in Terms of Color?

All my life I have been under the impression that man’s best friend viewed the world in shades of grey; that is until I was inspired to look into the matter. What I have found is that dogs actually do see color, just not in the same way as humans do. As we have learned in chapter nine, people with normal color vision need at least three wavelengths to match any wavelength in a test-field; this is known as trichromatic color vision. The central idea of the theory is that color vision depends on three receptor mechanisms, each with different spectral sensitivities. Our canine friends, however, rely on what is known as dichromatic color vision when perceiving colors.
Dichromatic vision differs from trichromatic vision in the sense that it only needs two wavelengths to match all other wavelengths in the spectrum, so what does that mean for Fido? Well, Jay Neitz from the University of California, tested the color vision of dogs by showing them three light panels in a row – two of the panels were the same color, while the third was different. The dogs’ task was to find the one that was different and to press that panel. If the dog was correct, he was rewarded with a treat that the computer delivered to the cup below that panel, and what Neitz found was that dogs actually do see color, but they fewer colors than us humans. For example, instead of seeing the rainbow as violet, blue, blue-green, green, yellow, orange and red, dogs perceive dark blue, light blue, grey, light yellow, darker yellow(which actually appears sort of brown), and very dark grey. The colors of yellow, green, and orange appear more yellowish and they see violet as looking more blue; blue-green is seen as grey and red are viewed as brownish.
So the next time you’re out trying to teach your best mate how to fetch and you find yourself becoming frustrated because he/she just doesn’t seem to get it; be open to the idea that it may not be because they are rebellious or ornery… the fact of the matter may very well be that they just didn’t see the object you choose because of its color.

Reference: http://www.psychologytoday.com/blog/canine-corner/200810/can-dogs-see-colors