Base colors

Extension gene
The extension gene controls the production of black and red pigment. It is one of the genes that determines the base color of horses.
Agouti gene
The agouti gene controls the distribution of black on the coat. It is one of the genes that determines the base color of horses.

Modifiers

Dilutions

MATP gene
The MATP gene is responsible for the dilutions cream, pearl, sunshine and snowdrop in horses.
TBX3 gene
The TBX3 gene is responsible for the dilution dun and non-dun1.

White patterns