There seems that in animals, certain colours are not highly thought of. In Standardbreds, grays have long had the reputation of being tough to handle. In Saddlebreds, Palominos and Pintos are thought to lack the quality that the "regular" colours have. In my experience, each animal is unique and colour is not an indication of mind or ability. For me, the last thing I look at in a Greyhound, or a horse, is the colour.