Horses typically come in two basic colors: black and red. All other shades stem from these two foundation colors.
Buckskin horses are yellow with black points (ears, mane and tail). Dun horses are variations on chestnut or bay base coats; due to an inherited trait they resemble zebras with dorsal stripes.
Bay horses are among the most commonly-seen horse coat colors and can be found across most breeds. Their characteristic combination of black pigment from agouti genes with reddish-brown base colors gives this shade its characteristic black points on mane, tail, ears and lower legs.
Genetically speaking, all bay horses carry at least one E allele (extension) and the dominant agouti gene; this combination restricts where black pigmentation appears in their hair.
Bays can range from solid colors to ones featuring white markings like face and leg stripes, star, snip and faded stripes. Roan bays can also be created through the leopard gene complex.
Black horses are striking for their beauty and elegance, which make them especially striking draft breeds such as the Percheron that were traditionally carried into battle by knights & can still be seen pulling carriages or farm machinery today. Other black breeds commonly seen are Friesian horses and Warlander hybrids that combine strength with poise similar to sport horses.
Black horses must possess both dominant extension genes (marked by an “EE or Ee”) as well as recessive agouti genes (A). Horses with two copies of Agouti A will be completely black, while those with just one allele may exhibit black pigmentation only on patterns on their body or points (lower legs, tail or mane). Black-based colors can also be diluted further to produce dapple gray, grullo or tobiano patterns.
Brown horses have brown or chestnut coats with tan markings on their flanks (belly) and head, and feature black manes, tails and lower legs. A true seal brown or liver chestnut does not feature dark topline coloration like some bays do; therefore their color can sometimes be confused with dark bay horses, especially among young foals. A proposed genetic modifier known as sooty or pangare lightens hairs enough that dark horses appear browner.
Multiple gene families produce lighter versions of base colors, such as chestnut and bay (as mentioned above), seal brown, and mahogany horses. Mahogany horses are those whose genetic black base coat has been suppressed by the agouti gene and only show black markings at certain points (head, ears and legs). Their coloring ranges from golden brown to deep mahogany in hue.
Buckskins are horses whose base coat color may either be bay or brown, yet have inherited the cream dilution gene to produce golden-colored horses with black points (mane, tail and legs).
Although duns and buckskins share many traits (such as their golden hue), duns differ considerably in that the latter are much darker in hue, while duns tend to have a more muted or “sooty” complexion than its counterpart. Most duns will have dark stockings with zebra stripes on their backs and also feature darker facial features with an additional dark’mask’ on their muzzle.
According to recessive and dominant trait math, two buckskin parents have a 25% chance of producing a base color foal (bay, chestnut or black), and 50% chance of producing a double cream dilute foal (palomino or cremello). Buckskins can also have shimmery effects thanks to white hairs interspersed throughout their bodies creating an alluring shimmery sheen.
The dun horse is the result of the dominant dilution gene. Like sorrel and bay horses, this trait dilutes both red and black base coat colors to produce its distinct coat coloration.
A classic dun is distinguished by a golden-tan color with black points and a dorsal stripe running down their back; these primitive markings resemble what wild horses use to protect themselves from predators.
The dun gene can produce both palomino and smoky grulla horses. A smoky grulla horse consists of any black or pinto horse with one agouti gene, two cream genes, and at least one dun gene. Many horses that do not belong to this genetic trait still possess dorsal stripes, although their edges tend to be less crisp and may not extend all the way down their tail; non-dun stripes often do not include leg barring either.
Palominos are double dilute horses characterized by golden-colored coats with white manes and tails, often favoured by royalty. They typically possess lean builds with solid muscles, making them an excellent candidate for royal use. Their golden hue has even been found in ancient Roman and Greek tapestries as well as paintings by Botticelli such as his 1481 work “The Adoration of Magi.”
Genetics behind palomino horses is intricate – to achieve their characteristic golden hue, horses require both a chestnut base coat and one copy of the cream gene – something not all palominos possess, leading to some having sandy hues instead.
Male palominos known as stallions and castrated ones as geldings; females are known as mares. Chocolate palominos with dark coats that show chocolate hues can be created by breeding liver chestnut with golden palomino.
Sorrel horses are distinguished by a distinct reddish-brown hue with copper highlights. Lacking the black pigment that gives chestnuts their characteristic brown shade, sorrels allow their red undertones to show through more vividly than with chestnuts. As with chestnuts, sorrels may sport flaxen manes and tails or feature white markings on their face, body or legs.
Sorrel horses may appear similar to chestnut horses, making it important to understand their differences. Sorrels feature a distinct red hue while chestnuts may vary between reddish brown, reddy-brown, rusty orange or even shades of rust. Sorrels tend to have lighter coloring without black marks or spots on their bodies and often lack any black marks altogether. Their gene, the MC1R recessive allele is also present in chestnuts, roans (known as red roans), Palominos similarly feature cream dilution allele.