I havent seen anyone commenting on the fact that Nightmare in Silver, the title of Doctor Whos upcoming Cybermen episode scripted by Neil Gaiman, appears to be a nod to the titles of six short stories Nightmare in Gray, Nightmare in Green, Nightmare in White, Nightmare in Blue, Nightmare in Yellow, and Nightmare in Red in Nightmares and Geezenstacks (collected here) by the incomparable Fredric Brown (of whose work Gaiman is known to be a fan).
So I hereby comment on it.
FWIW, other admirers of Browns work include Ayn Rand, Mickey Spillane, Robert Heinlein, and Philip K. Dick.