J.K Rowling: Black Hermione is a brilliant way to teach idiots heroes don't have to be white

With the a play centered around grown-up characters from her popular Harry Potter books set to open on Tuesday, author J.K. Rowling pushed about at fans she described as "idiots" who are still critical of a black actress playing Potter confederate Hermione Granger.

Many fans of the enormously popular books were outraged last December when casting for Harry Potter and the Cursed Child was announced, and Lawrence Olivier award-winning actress Noma Dumezweni -- who is black -- was chosen to play Hermione.

Responding at the time, Rowling tweeted: "Canon: brown eyes, frizzy hair and very clever. White skin was never specified. Rowling loves black Hermione."

In an interview with the Guardian, Rowling hearkened back to the controversy and ridiculed those she called the "racists" who seem to feel that they know her fictional charters better than she does.

"Noma was chosen because she was the best actress for the job. When John (Tiffany) told me he’d cast her, I said, ‘Oh, that’s fabulous’ because I’d seen her in a workshop and she was fabulous,” Rowling explained.

“I had a bunch of racists telling me that because Hermione ‘turned white’ – that is, lost colour from her face after a shock – that she must be a white woman, which I have a great deal of difficulty with,” she continued. "But I decided not to get too agitated about it and simply state quite firmly that Hermione can be a black woman with my absolute blessing and enthusiasm.”

“With my experience of social media, I thought that idiots were going to idiot. But what can you say? That’s the way the world is," she added.

According to playwright/director Tiffany who worked in conjunction with Jack Thorne and Rowling on the script, most criticism came from the "dark side" -- with the writer also pointing at social media.

"The anonymity breeds horrors so after a while I stopped reading it,” he explained. "But what shocked me was the way people couldn’t visualize a non-white person as the hero of a story. It’s therefore brilliant that this has happened.”