🎨 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.  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. 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. 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 but any color can be a carrier.  Sooty Bay Sooty Dark Bay Liver Chestnut Sooty Buckskin 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 Graying Process                                   Bay Base Graying Process Chestnut Base Graying Process Gray Final Forms