Dogs can see some colors, but not the same way humans do. Humans have three different types of cones in their eyes, which allows us to identify combinations of red, blue, and green. Dogs, on the other hand, have only two types of cones, which means they can only discern blue and yellow. As a result, dogs are red-green color blind. Because dogs have fewer cones in their eyes, they cant see the same spectrum of colors that humans can see, nor can they see them as brightly as we do. For example, red appears as a dark brownish-gray hue or even as black to a dog. Additionally, shades of yellow, orange, and green all appear as varying shades of yellow to dogs. Therefore, if you want to choose a toy for your dog, blue and yellow toys are the best options as they are the colors that dogs can see the best.