I always thought that dogs were color blind.
Cookie goes for red though. Anything red, and she'll have it in her mouth.
Last week I went for a walk with her, and an old woman walked in the forest too with a red shopping bag. I didn't think anything of it and had Cookie off her leash. My-of-my, did she take of to the woman and started to pull the bag out of the womans hand! It was terrible and I was so ashamed. Thankfully she thought the situation was hilarious, otherwise I had a very big problem.

Guess some dogs can see colors, or maybe Cookie is just very smart. Yeah, that might be it