Equine coat color genetics determine a horse's coat color. There are many different coat color possibilities, but all colors are produced by the action of only a few genes.
The simplest genetic default color of all domesticated horses can be described as either "Red" or "Black" based, depending on whether a gene known as the "Extension" gene is present. When no other genes are active, a "red" horse is the color popularly known as a chestnut, red or sorrel (two red alleles or "e/e". Black coat color occurs when the Extension gene "E" is present, causing the horse to appear black in the absence of any further modifiers.
The Agouti gene "A" can be recognized only in "non-red" horses; it determines whether black color is uniform, creating a black horse, or restricted to the extremities of the body (lower legs, mane, tail, ear tips, etc) creating a Bay horse, and so on.
Click on the color gene buttons below (left column) and see how the colors work!
**We are currently reworking our color tool to make it better, faster, and phone compatible. Please stay tuned and we'll re-release this feature soon!