Certain Horse is a term used to describe a variety of horse breeds. Grey, GRAY, Roan, STUD, PINTO, RACER, and SORREL are all types of horses that fall under this category. Grey and GRAY horses are usually solid-colored with a mixture of black and white hairs. Roan horses have a mix of white and red or bay hairs. STUD horses are usually stallions that are used for breeding. PINTO horses have a coat of two or more colors, usually white and brown. Racers are horses that are bred for speed and agility. SORREL horses have a reddish-brown coat.