Sarah 'Ash' Preece Well duh, it's a joke, and besides, yes they are.
http://www.squidoo.com/aredogscolorblind
http://www.straightdope.com/columns/read/366/are-cats-and-dogs-really-color-blind-how-do-they-know
Sure, they can see some colors, but not all the colors we can.
This isn't technically true. Usually dogs are aggressive towards black dogs specially if the dog is reactive. The main reason is they can't read the black dogs facial features and expressions.