How did my foal end up wtih that much white?

[Malakai10]

So, color genes from grandparents can affect on the Foal's color, right?

Also i know what is a Brown (It's the easiest Horse Coat Color to learn). i just wanted to give example, like her color is more darker than her parents.

Technically, every single ancestor of that horse affects the coat colour - however, a foal cannot be a colour that neither parent carries the genes for. So, say you have this scenario:

Granddam (maternal): palomino (e/e Cr/cr)

Grandsire (maternal): palomino (e/e Cr/cr)

Granddam (paternal): palomino (e/e Cr/cr)

Grandsire (paternal): chestnut (e/e)

Dam: chestnut (e/e)

Sire: chestnut (e/e)

Then the offspring can only be chestnut because the cream gene is dominant - it cannot 'skip' generations. Now, on the other hand, if you have this scenario:

Granddam (maternal): apricot (e/e prl/prl)

Grandsire (maternal): chestnut (e/e)

Granddam (paternal): palomino pearl (e/e Cr/prl)

Grandsire (paternal): chestnut (e/e)

Dam: chestnut (e/e prl/cr)

Sire: chestnut (e/e prl/cr)

The offspring can end up being a plain chestnut (e/e cr/cr), a chestnut carrying pearl (e/e prl/cr) or an apricot (prl/prl)

Apricot (chestnut with double pearl) is recessive. It only expresses when two copies of the gene are present OR one copy of pearl and one copy of cream are present. So, a horse with base chestnut that is heterozygous for pearl (e/e prl/cr) will look exactly the same as a normal chestnut (e/e)

So, in essence: a foal can only 'inherit' colour genes from their grandparents if the parent(s) also carry that gene.

You keep calling her brown but she's chestnut. Brown is one of the agouti genes and only expresses when a horse has at least one extension (black) gene.

[BlackOak2]

To be clear, if Malakai10's response leaves any questions left.

This horse:


Is a bay dun pangare tobiano.
The only white 'paint-like' markings in the game currently (including socks and stars) is the direct result of the tobiano gene.
From what we have discovered, it appears to work much like Lp. You need the 'switch' gene and also the patterning genes for any of the tobiano patterns to appear. So we can have a horse with the switch gene and no patterns or a horse with pattern genes and no switch, both, of which, will appear to have no tobiano at all, but they CAN produce a horse with patterning.
Tobiano also works on a build-able style, which means, you build-upon the coat pattern to get more coat pattern.