I'm guessing that you Googled "black and white percula" and it's the only site that discusses a black and white percula as a real fish. Let's keep in mind that Animal Planet is also the (former) home of Tanked.
All kidding aside, I tend to push folks when they make statements that appear to be truthful, but don't have the facts to back it up. Citing one online source cannot be taken as credible, especially when it's from a network that's based more on entertainment than education.
When it comes to IDing fish, particularly clownfish and more specifically the ocellaris and percula species, there are really only two species, and they break down into color morphs, the black and white ocellaris (sometimes referred to as Darwin ocellaris) being one of them.