"Makeup developed in the 1940s for black-and-white television. [...] The new cameras transmitted images in negative. The company's solution was a makeup that looked highly unnatural in real life but appeared natural when reversed on screen."
That explanation is obvious nonsense. This explanation is slightly less nonsensical, but it still doesn't make much sense to me without an A/B comparison of shots like this and what they looked like on screen, which I've been unable to find.