#epona

Horses all have one of three "base coats": chestnut, bay, and black. Chestnut (or "red") and black are opposite sides of a coin, with black (E) being dominant to chestnut (e). Bay is caused by a different gene, agouti, which "pushes" black to the extremities, giving a horse with a brownish body and black mane/tail & legs. Agouti (A) is dominant, but doesn't do anything if the horse doesn't have black.

Cream (Cr) is a dominant gene that lightens the whole horse, but mostly the red side of the coin. When heterozygous (only one copy), it makes a chestnut a palomino, a bay a buckskin, and a black horse a smokey black horse. When homozygous, it makes a chestnut a cremello, a bay a pearlino, and a black horse a smokey cream horse.

Flaxen (f) is a recessive gene that lightens the mane/tail on a chestnut horse, making the mane/tail appear cream or white. Silver (Z) is a dominant gene that lightens the mane/tail on a black or bay horse, making the mane/tail appear silver or white. Flaxen doesn't show on black & bay horses and silver doesn't show on on chestnut horses.

There are other genes that modify a horse's base coloring, such as champagne or roan, but Epona either doesn't have them or we have no proof that she does. She's always depicted as a flaxen chestnut or silver bay. Note the presence/absence of black and the reddish brown (not "yellowish") color of her coat.

She also has white markings. However, they don't appear to be any of the genetically defined, "unusual white markings", such as leopard or pinto. At most, she'd have sabino, due to having four white markings on her legs and a white patch on her face. However, that doesn't appear to be the case. If it was, we'd be looking for very high, jagged socks and a thick, irregular "blaze" that covers her muzzle. She also lacks the flecking and equally jagged stomach patches sometimes seen with sabinos.

Instead, she has what are known as your bog-standard "common white markings". Unlike the above markings, these ones have no clear cause. Like, we know a horse can inherit a "good chance of having them", in general, but we have no evidence that specific marks, like a star on the forehead, are genetic. Which is why you can't really "breed for them", and why even the strictest studbooks (which dictate the colors, patterns, shape, etc. a purebred can have) handwave them.

Which means there isn't exactly specific standard terms for what a given mark is called. What one person calls a "bald face", another calls a "bonnet" or "paper face". Often, these work in-tandem with your unusual white markings, like with my use of "blaze" for the sabino's face marking. Because it's just easier that way.

What happens if Epona was given the bunny hood?

( video based on an old post by @hyrule-warriors-headcanons )