Seen young Gold Ship drawn like these quite a few times by various artists. Though some just go with her default hair colors.

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Anyway, the so-called "grey" horses have a greying gene that gradually turns their coat grey or white over time. The skin underneath is usually still black (unlike actual "white" horses, which have pink). "Grey" horses are born with various different coat colors but they start growing more and more white hairs over time until they end up with a grey or white-looking coat "dappled" with darker spots and stripes indicative of their original colors.

The real-life Gold Ship looked like this during his younger years. He still has that white "blaze" stripe on his face though it's getting harder to see now as his coat gets whiter and whiter over time (it was easier to see during his racing days).

And here's I think is supposed to be Gold Golden, one of Gold Ship's sons. In this next pic you can see the coat colors starting the fade. And this is what he looks like now.