Isn't there a Seinfeld episode where Jerry proves that black and white foods just don't go well together? I think it was the black-and-white cookie that did him in and made him puke for the first time in decades.
Now McDonald's in China, who probably don't watch the Seinfeld reruns as much as we do, have introduced a black and white burger. They are actually two separate burgers-- one with a black bun with white sesame seeds; the other a white bun with, you guessed it, black sesame seeds. The black burger reportedly contains black pepper sauce with chopped onions and the white one has a sweet and spicy flavor.
But according to a site called TheBeijinger there's an inside joke here that only Chinese people would get:
...a colleague informed us they're a play on a Chinese phrase: heibai liangdao tongchi (黑白两道通吃), which describes people who are so well-connected with both the government (that's the white side) and organized crime ("black society," as it's called in Chinese) that they can "eat from both sides." In other words, someone who has a foot in both camps.
Hmm. A Seinfeld connection would have been funnier.