Where did that come from?

!!! your right? wth! maybe its a genetic gap thing from generation? you know it happens in a genetic map where the ancestors have brown hair

Could be...or either Bing Eun Seoul or Cheon Ma have power that change the colour of their hair so maybe it was originally brown but than it changed? That could also explain why her hair is dark brown....but in the Novel she has jet black hair...that would suit her more...