I'm looking for a young adult book I read sometime in the late 90s or early 2000s, probably published in the late 80s or 90s. It's about a girl with four hair colors, like red, black, silver and blonde. I don't remember her name.
She is new to the area where the book is set and is somehow being held captive or controlled by a woman who tells her that her hair is ugly. The girl is staying in a large house, possibly for orphans and the captor may be her foster mother.
The girl is a witch or possesses a power and her hair is part of this power. Her captor wants to use the power the girl has and torments her throughout the book. The captor/foster mother may have had several 'henchmen' watching the girl as well.
The only scene I remember was the girl ice skating with some children from school and her hair blowing in the wind. Someone tries to touch her hair and compliments her on it, which surprises the girl because she thinks her hair is ugly.