Wikipedia
Seal brown is a hair coat color of horses characterized by a near-black body color; with black points, the mane, tail and legs; but also reddish or tan areas around the eyes, muzzle, behind the elbow and in front of the stifle. The term is not to be confused with "brown", which is used by some breed registries to refer to either a seal brown horse or to a dark bay without the additional characteristics of seal brown genetics.
Like bay, the seal brown color is produced by the Agouti ("A") gene acting upon a genetically black base coat, suppressing the black into point coloration and allowing the underlying reddish or brownish color to appear. However seal brown is designated with the qualifier A The genetic study of seal brown is relatively new. Several theories were advanced in the last century to explain the heredity of the seal brown coat, and while a DNA test said to detect the seal brown (A) allele was developed, the test was never subjected to peer review and due to unreliable results was subsequently pulled from the market.
The genetically and visually related dark bay coat color, which also features black points and a near-black body, differs from true seal brown in the absence of tan markings. The term "seal brown" is to be distinguished from the term "brown." Another mimic is the liver chestnut, an all-over dark brown coat including mane and tail, that is sometimes confused with seal brown. However, true seal browns have black points, while liver chestnuts do not.
Usage examples of "seal brown".
Star, crooked stripe, snip, all against a background of seal brown.