If I were a more poetic person I might assign some fantastical metaphor to how my originally brown hair turned jet black like my father's when I hit puberty, with its colour only returning when I transitioned, once more becoming brown like my mother's. But I know that's just an effect of the hormone therapy.
Still, it's something.
sounds like it could make a great metaphor for depression caused by dysphoria. the colour draining as the body grew more distant from how it was supposed to be and returning when it starts matching who you are.