But why? It's a British book and Britian is something like 82% white isn't it? And back in the 80s when the stories were supposed to be set it must have been more like 92% white.
But it isn't set in 90's Britain is it? It's set in a fantasy world or witches and wizards.
Hasn't JK Rowling said that she didn't mention the colour of Hermione's skin in any of the books?