Can Dogs See in Color?

Ever wonder whether dogs see in color like humans do, or only in black and white? Does it matter to your dog if you humiliate him by making him wear a blue sweater, or will a yellow one be just as humiliating? Modern science has the answer:

Dogs see in color, but not very well.

Eyes have two cells that receive light: rods and cones. Rods tell us how bright or dim a light is, i.e. how "white" or "black" it is. Cones tell us what color the light is. Humans have three kinds of cones that each detect color at different wavelengths, which are basically yellow, violet, and green. Just like old television sets have little squares of blue, green, and red to make up the full picture, every color we see is a combination of cones working at different intensities.

Color blind humans are missing one type of cone. Dogs only have two types of cones, the yellow and the violet, so technically, all dogs are color blind by human standards. For dogs, orange, yellow, and green are seen as yellow, blue-green is seen as white, red is seen as close to black, and there is little distinction between the blues as they get darker.