🎨 Modifiers
Color Modifiers
Modifiers alter the appearance of the base coat but do not dilute it.
Flaxen (F)
Flaxen is a recessive modifier that lightens the mane and tail of chestnut horses. Depending on expression, flaxen can range from a slightly lighter mane and tail to a nearly white mane and tail.
Inheritance
| Genotype | Result |
|---|---|
| F/F | Flaxen |
| F/f | Carrier |
| f/f | Non-Flaxen |
Because flaxen is recessive, a horse must inherit a flaxen allele from both parents in order to visually express it.
Expression
Flaxen only affects chestnut horses. Bay and black horses may carry flaxen but will not visually express it.
Flaxen Chestnut Flaxen Liver Chestnut Flaxen Red Chestnut
Silver (Z)
Silver is a dominant modifier that affects black pigment. It lightens the mane and tail while having no effect on red pigment.
Inheritance
| Genotype | Result |
|---|---|
| Z/Z | Silver |
| Z/z | Silver |
| z/z | Non-Silver |
Only one copy of silver is required for expression.
Expression
Chestnut horses may carry silver but will not visually express it because they do not produce black pigment.
Silver Bay Silver Black
Sooty (Sty)
Sooty is a dominant modifier that adds dark hairs throughout the coat. Expression can range from subtle dark shading to heavy darkening across the entire body.
Inheritance
| Genotype | Result |
|---|---|
| Sty/Sty | Sooty |
| Sty/sty | Sooty |
| sty/sty | Non-Sooty |
Only one copy is required for expression.
Expression
Sooty affects bay and chestnut based horses
Sooty Bay Sooty Dark Bay Sooty Seal Bay
Sooty Buckskin Liver Chestnut Chocolate Palomino
Gray (G)
Gray is a dominant modifier that causes progressive depigmentation over time.
A gray horse is born its original colour and gradually lightens as it ages.
Inheritance
| Genotype | Result |
|---|---|
| G/G | Gray |
| G/g | Gray |
| g/g | Non-Gray |
Only one copy is required for expression.
Expression
Gray can occur on any base colour.
Examples:
- Black → Gray
- Bay → Rose Gray
- Chestnut → Rose Gray
The horse's original color remains genetically present underneath the graying process.
Black Base - Stage 0 Stage 1 Stage 2
Stage 3 Stage 4 Stage 5
Final Form A Final Form B
Bay Base - Stage 0 OR Chestnut Bay - Stage 0 Stage 1
Stage 2 Stage 3 Stage 4
Final Form A Final Form B