Your complete guide to horse breeds, care, and riding from around the world

Horse Colors

Horse Colors

Agouti, the “bay” gene

Our first and most common color modifier in horse genetics is Agouti, also known as the "bay" gene.


bay horse pictureBay and Brown are actually a modification of Black. In other words, bays and browns are black horses with a dominant modifying gene called AGOUTI added.


Agouti acts to restrict the black of the black horse to just specific points, which are the mane, tail and lower legs. This allows the red that is "uncovered" by agouti to show through on the body of the horse in varying degrees, depending on the type of Agouti present.


Chestnuts can carry agouti, but it won't show on them as they have no black hair to restrict to the points. bay horse pictureThey can, of course, pass it on to their offspring.


Black horses cannot have agouti, because if they did, they'd be bay, not black.


A black and  chestnut cross might produce a bay foal. This happened because the agouti, or bay gene, actually came from the chestnut parent, and the black base color came from the black parent.


It is theorized that there are three different types of agouti. The Agouti which causes "regular" bay is written as an "A." The "wild type" Agouti, which results in a light bay horse with very little black on the legs, (usually just around the fetlocks) is written as "A+."

bay horse pictureBrown, or what is sometimes called "seal brown," (a nearly black horse with reddish areas on the muzzle and flanks) is written "At."


A horse will have some combination of the three types, one of the three types plus one non-agouti gene (one non-agouti gene is written as "a"), or have no agouti at all (written as "aa").

Silver Dapple vs Chocolate Palomino

Often called a chocolate palomino, this coloring is actually a Silver Dapple--a true black horse with a modifying gene (Z). The Silver Dapple gene turns the black hairs of the mane and tail to a silvery white, and the body color to a chocolate. A true chocolate palomino is a liver chestnut with a Cream gene. (ee, Cr).





This morgan is a silver dapple, often confused with a chocolate palomino.


 


 


 


 


 


 


 


 


 


 


 


 


This Gypsy Vanner mare shows the more typical dappling of this color. She is Lady Godiva, imported and owned by Mulberry Lane Farms


Silver Dapple Gypsy Vanner mare, Lady Godiva MLF