Use our free horse color calculator to predict your foal’s coat color from parent genetics — covering base colors, dilute genes, cream, dun, silver, roan, and pattern modifiers.
How Horse Coat Color Genetics Work
All horse coat colors come from two pigments: eumelanin (black) and phaeomelanin (red/yellow). Two genes control which pigment appears — the Extension (E) gene and the Agouti (A) gene. Every other color is a modification of these base combinations.
The Three Base Colors
| Base Color | Genotype | Appearance |
|---|---|---|
| Chestnut / Sorrel | ee | Red/orange body; mane and tail same or flaxen. No black pigment. |
| Bay | E_ A_ | Brown/red body with black mane, tail, and legs. |
| Black | E_ aa | Solid black body, mane, tail, and legs. |
Horse Color Calculator: Foal Color Predictions
| Parent 1 | Parent 2 | Possible Foal Colors | Probability |
|---|---|---|---|
| Chestnut (ee) | Chestnut (ee) | Chestnut only | 100% chestnut |
| Chestnut (ee) | Bay (EeAa) | Chestnut or Bay | 50% chestnut, 50% bay |
| Bay (EeAa) | Bay (EeAa) | Bay, Chestnut, or Black | 56% bay, 19% chestnut, 6% black |
| Black (Eeaa) | Black (Eeaa) | Black or Chestnut | 75% black, 25% chestnut |
| Bay (EEAa) | Black (EEaa) | Bay or Black | 50% bay, 50% black |
| Palomino (ee nCr) | Palomino (ee nCr) | Palomino, Chestnut, or Cremello | 50% palomino, 25% chestnut, 25% cremello |
Cream Gene (Cr) Effects
| Base Color | Single Cream (nCr) | Double Cream (CrCr) |
|---|---|---|
| Chestnut | Palomino (gold body, white/cream mane) | Cremello (very pale cream, blue eyes) |
| Bay | Buckskin (tan body, black points) | Perlino (cream body, darker points, blue eyes) |
| Black | Smoky Black (appears black, carries cream) | Smoky Cream (pale cream, blue eyes) |
Dun Gene Effects
| Base Color | With Dun | Key Features |
|---|---|---|
| Chestnut | Red Dun | Muted red-gold; red dorsal stripe; leg barring |
| Bay | Classic Dun (Bay Dun) | Tan body; black points; dark dorsal stripe |
| Black | Grulla (Grullo) | Mouse-grey; black dorsal stripe; black points |
Complete Horse Coat Color Reference Chart
| Color | Genetic Basis | Description |
|---|---|---|
| Chestnut/Sorrel | ee | Red/orange body; same or flaxen mane/tail |
| Bay | E_ A_ | Brown body; black mane, tail, legs |
| Black | E_ aa | Solid black throughout |
| Palomino | ee nCr | Gold body; white/cream mane and tail |
| Buckskin | E_ A_ nCr | Tan/gold body; black points |
| Cremello | ee CrCr | Very pale cream; blue eyes |
| Perlino | E_ A_ CrCr | Cream body; darker points; blue eyes |
| Dun | E_ A_ D_ | Tan body; black points; dorsal stripe |
| Grulla | E_ aa D_ | Mouse-grey; black dorsal stripe |
| Roan | any + Rn_ | Base color with white hairs mixed in body |
| Grey | any + G_ | Born any color; whitens progressively with age |
| Champagne | any + Ch_ | Metallic sheen; mottled skin; amber/hazel eyes |
Frequently Asked Questions
What determines a horse’s coat color?
Horse coat color is controlled primarily by the Extension (E) gene, which determines whether black pigment can be produced, and the Agouti (A) gene, which controls where black pigment is distributed. All other colors — palomino, buckskin, dun, roan, grey — result from additional modifier genes acting on these three base colors (chestnut, bay, and black).
Can two chestnut horses produce a bay foal?
No. Two chestnut horses (both ee genotype) cannot produce a bay or black foal because bay and black require at least one dominant E allele. Two chestnuts will always produce a chestnut foal — this is one of the most reliable rules in equine color genetics.
Can a palomino breed true?
No. Palomino is a single-copy cream on chestnut (ee nCr). Breeding two palominos produces approximately 25% chestnut, 50% palomino, and 25% cremello. You can never guarantee a palomino foal from two palomino parents.
How do I calculate my foal’s color?
Start with both parents’ genotypes at the E and A loci, apply Mendelian inheritance for each gene, then layer modifier genes (Cream, Dun, Roan, Grey) the same way. For the most accurate prediction before breeding, genetic testing of both parents through UC Davis or Animal Genetics is recommended.
What is the rarest horse coat color?
Truly rare colors include brindle (chimerism, not a true genetic color), mushroom (dilutes chestnuts to pale sepia, mainly Shetlands), and double dilutes like Cremello and Perlino. True white horses with pink skin (carrying W gene mutations) are also rare.