why are dogs colorblind?

I don't think they are. my Greyhound loves anything purple. one of his favourite toys is a large purple ball, and we had two toys the same once, squeaky hedgehogs. he only played with the purple one, and wasn't interested at all in the yellow one. he's always more interested in things that are purple.

I have never heard that before, I wonder if my dog is colorblind.

Don't who stated that dogs were colour blind Gosh now I am confused Everytime I told my dog Dino to fetch me a Blue He would go the fridge and get me one Not a Coors Light but a Labatt Blue He wouldn't even touch the Lucky lager No definitely not colour blind LOL Wendy

dogs can see many colors, they just have red/green color blindness. They definitely shouldn't be allowed to drive, lol! They can actually see better in dim light and some (like my greyhound, for instance) actually have better vision as far as distance goes than people (but I'm really myopic, so we make a great pair). I don't think its a matter of breeding per se but more a matter of what dogs evolve from. They are close relatives to wolves, who are predators, and need good night vision far more than the ability to distinguish red from green. Dogs can see shades of brown, blue, yellow, purples, and grays, so they can see enough to go after a rabbit or a squirrel.

Oh are they colorblind really? I never heard about that before, But well, thanks for sharing it with us!