Like Ned Stark in GOT. Her dad is blond, she has dark hair, and yet Foxy is a freckeld readhead...
I don't remember her, but since red hair is a recessive trait two people without red hair can have a red haired child. You can even make reasonable assumptions about people's genes from their offspring's hair colour.
My grandma had black hair, my grandpa had brown hair. They had 3 brown haired kids, 1 black haired kid and a redhead. So we can assume with a reasonable degree of confidence that the 3 with brown hair inherited my grandpa's brown hair gene and my grandmas red hair gene. The black haired on got grandma's black hair gene and either of grandpa's hair colour genes. Then the redhead got double red.
Of course this was all assuming the dev was even thinking about this when designing Foxy. Most people don't think so deeply about hair colour genetics. Then there's also the fact that red hair can manifest without the paired gene. I'll see if I can find the paper about that.
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