You could probably sell one of these into every concert theatre in the world. I'm wracking my brain and exercising my google-fu, but I can't seem to find/remember which famous musician wanted only one color of candy on their rider. Or was it everything except the green ones. Or something like that.
It was just a test for the venue provider, which is a really clever way of sneaking in a kill-switch as well.
> So, when I would walk backstage, if I saw a brown M&M in that bowl ... well, line-check the entire production. Guaranteed you're going to arrive at a technical error. They didn't read the contract. Guaranteed you'd run into a problem. Sometimes it would threaten to just destroy the whole show. Something like, literally, life-threatening.