Not sure if this qualifies as unusual, but it's a 3 light setup I did for a friend's engagement shoot (we shot it like an editorial, so each image was completely different from the last). First is a bare flash gelled red controlled by barn doors on him, second is a purple gelled flash bare on her (hidden behind him), and the third is a flash into a 5' Octa in the hallway. That light is diffused with fog in a can, and the blue color in the rest of the room is from an extremely cool white balance.