[Lee Stewart]

Most people think dogs see in black and white, but they actually see in shades of yellow and green. The color spectrum we see is thanks to the rods and cones in our eyes, which are responsible for interpreting color by wavelength. Humans (and primates) see three wavelengths of color (red, blue, and yellow) but dogs only have cones that see two (yellow and blue). Basically, to a dog, anything that is a shade of red will just be interpreted as a shade of green.