Is Your Furry Little Friend Color Blind

Dogs are not completely color blind since they have a dichromatic color perception. Unlike humans who have three different color sensitive cone cells in their retina (red, green and blue) dogs have only two (yellow and blue)
This does not mean that dogs can't see green or red objects! It only means that they can't distinguish green, yellow or red objects based on their color. However they can still distinguish a red ball from a green one if there is a difference in the perceived brightness of the two.
The color vision of dogs is similar to a person suffering from deuteranopia (red-green color blindness). Red, yellow andgreen are perceived as one hue. Blue and purple are perceived as a second hue. Cyan and magenta are perceived as a neutral hue (grey).