Tobiano is a dominant gene, meaning that a horse sporting a tobiano pattern must have at least one parent carrying the tobiano gene. Genetic tests are available that can determine positively an overo or tobiano pattern. According to the Australian Paint Horse Association, the test for tobiano horses looks for the dominant "T" gene.
Dark bay vs. seal brown. Bay horses, which have a black mane, tail, and legs with a mixture of red and black hairs on the body coat, and seal brown horses, which have primarily black coats in addition to black "points", with reddish or tan hairs around their muzzle, eyes, girth and flanks have one of two genotypes at the Agouti locus: A/A A/a.
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 characteristic of all bay horses, while liver chestnuts do not.
Solid Paint-Bred. A good horse is a good horse, regardless of its color. And while color can be a major asset, a lack of color does not limit your opportunity for success with the American Paint Horse Association. Not all foals will have flashy color patterns, but APHA’s wide array of programs are open to all APHA-registered horses.
The American Paint Horse is a breed of horse that combines both the conformational characteristics of a western stock horse with a pinto spotting pattern of white and dark coat colors. Developed from a base of spotted horses with Quarter Horse and Thoroughbred bloodlines, the American Paint Horse Association (APHA) breed registry is now one of the largest in North America.