When something is too insignificant to warrant an explanation or reason behind it. Also more generally used to describe people, places, or things that don't matter or are unknown, especially in comparison to something more popular or significant. Derived from articles on Wikipedia that are in red because no one has cared to write an article for them.
Person 1: "Samuel L Jackson has been in a lot of movies."
Person 2: "Yeah, but most of them are Wiki Red."
Person 1: "Dude, remember Charles from Kindergarten, I saw him at the bar last night, he's a pilot now!"
Person 2: "Charles? Who cares about Wiki Red ass Charles, I just hit the damn lottery!"
Person 1: "Meh, did you hear about the inside deal Wall Street execs are making with Lobbyist in the Senate?"
Person 2: "No!? That's some Wiki Red shit."