This Wikipedia page is a great resource.
- BAY: Body color ranging from tan through red to reddish brown; mane and tail black, usually black on lower legs.
- BLACK: Body color true black without light areas; mane and tail black.
- BROWN: Body color brown or black with light areas at the muzzle, eyes, flank, and inside upper legs; mane and tail black.
- SORREL: Body color reddish or copper-red; mane and tail usually same color, but may be flaxen.
- CHESTNUT: Body color dark red or reddish-brown; mane and tail usually dark red or reddish-brown, but may be flaxen.
- DUN: Body color yellowish or gold; mane may be black or brown, has dorsal stripe, and usually zebra stripes on legs, and transverse stripe over withers.
- BUCKSKIN: Body color yellowish or gold; mane and tail black, black on lower legs; buckskins do not have dorsal stripe.
- RED DUN: A form of dun with a body color yellowish or flesh colored; mane and tail are red, reddish, yellow, white, or mixed; has a red or reddish dorsal stripe and usually red or reddish zebra stripes on legs and transverse stripe over withers.
- GRULLA: Body color smoky or mouse-colored (not a mixture of black and white hairs, but each hair mouse-colored); mane and tail black, usually has a black dorsal stripe and black on lower legs.
- PALOMINOS: Body color a golden yellow, mane and tail white; Palominos do not have dorsal stripes.
- GRAY: Mixture of white with any other colored hairs; after birth, solid colored or almost solid covered and get lighter with age as more hairs appear.
- RED ROAN: A more or less uniform mixture of white with red hairs.
- BLUE ROAN: More or less uniform mixture of white and black hairs; usually with a few red hairs.
- APPALOOSA: Any base coat color with spots. (Please specify the primary coat color on the application, such as bay with snowflakes). Can vary from “snowflakes” over hips; white hip with dark spots; white coat with “Dalmatian” spots; roaning with darker spots scattered over whole body.
- PINTO: Combination of white and any other color(s) in large spots. (Please specify the primary coat color on the application, such as chestnut pinto.)