What is the name for a horse that is entirely black in color? The answer is black.
Black is one of the basic horse coat colors. A truly black horse has black hair over its body, mane, tail, muzzle, and legs, although it may still have white markings such as a blaze or socks. The horse generally has black skin and dark brown eyes as well.
Black horses are sometimes mistaken for very dark bay or chestnut horses. Sun exposure can cause a black coat to fade or develop a rusty appearance, especially in the mane and tail. Looking closely at the fine hair around the eyes and muzzle can help distinguish a sun-bleached black horse from a dark bay, which usually has reddish or brown hairs in those areas.
Coat color also has a genetic basis. The extension gene allows black pigment to be produced, while the agouti gene influences whether that pigment is restricted to the points, as in a bay horse. Breeds known for frequently producing black horses include Friesians and Murgese.