Black horse

A black horse has a coat that is completely black, with no reddish or brownish areas. This deep black color is different from dark chestnuts or bays, which might look similar at first glance. Black horses usually have dark brown eyes and black skin.

Even though their coats look black all over, some black horses may have areas of white hair, called white markings. Under these white areas, the skin might be pink, and if the white markings cover one or both eyes, the eyes can sometimes appear blue.

When black horses are exposed to sunlight and sweat, their coats can look lighter, almost like bay or seal brown. But by looking closely at the hair around the eyes, muzzle, and genitals, you can still tell they are black. Certain breeds, like the Friesian horse, Murgese, and Ariegeois, are almost always black, and the color is also common in other breeds such as the Fell pony and Dales pony.

Visual identification

When trying to figure out the color of a horse, ignore any white markings. These white spots or patterns, like pinto or leopard, don’t change the horse’s true color underneath.

Baby black horses, called foals, are often born looking gray but can be darker. Sometimes they look like grullo or bay dun because of markings that fade as they grow. Black baby horses have dark skin and eyes. If a baby horse looks almost fully black, it might turn gray later, especially if one of its parents is a gray horse. Signs of this include white hairs around the eyes and muzzle. Some gray Lipizzaner horses are born black.

Fully grown black horses have coats that are completely black, even if the sun has lightened some parts. A sun-bleached black horse might look like a dark bay, but careful looking, especially at the fine hairs around the eyes and muzzle, can help tell the difference. When black horses get sun-bleached, their mane and tail often lighten the most, and the rest of the coat might look rusty. A sun-bleached black horse can sometimes be confused with a smoky black, but there isn’t a sure way to tell them apart just by looking.

Black mimics

• Dark bay or seal brown: Some very dark bay horses look almost black, but they still have some red in their coat. Horses that look black but have tan or reddish hair near their eyes, nose, armpits, or legs are called "seal brown," "mahogany bay," or "black bay." These colors are different from true black and can be checked with a DNA test.
• Liver chestnut: Some chestnut horses are so dark they seem black and are called "black chestnuts." But even the darkest liver chestnuts have some red in their coat, usually near the lower legs, mane, or tail. They don’t have true black pigment. This can be confirmed with DNA testing. Liver chestnut is common in the Morgan horse.
• Smoky black: When the cream gene mixes with a black coat, it makes little change, so smoky blacks look very similar to true blacks. A smoky black usually has at least one cream parent, may be born a light gray color with blue eyes, and often keeps reddish hair inside the ears when grown up.

Genetic identification

Main article: Equine coat color genetics

When we talk about horse coat colors, black is considered a basic color, just like red. This makes it easier to understand how other color genes work. Colors that start with a black base include grullo (also called blue dun), smoky black, smoky cream, silver black, classic champagne, and blue roan. Sometimes, colors like bay, seal brown, buckskin, and bay dun are also included.

The genetics of a black horse are fairly simple. Two main genes control the black color: Extension and Agouti. If a horse has the right version of the Extension gene, it can make black pigment in its hair. Without this gene, the horse will have a red coat instead. The Agouti gene decides where the black pigment appears. If this gene is not active, the horse will have a completely black coat.

A true black horse has the right version of the Extension gene and a certain version of the Agouti gene. Scientists can use a DNA test on a hair with its root to check these genes. This helps confirm if a horse that looks black is truly black and not just a dark bay or chestnut.