Have you ever wondered why someone is “seeing red” when they’re mad, or “feeling blue” when they’re depressed? Why are people “green with jealousy” or said to be “yellow” if they’re thought a coward? Why is someone who is shy called a “shrinking violet?” (I thought about not including that one, as it refers to the flower rather than the color, but in the end, decided to toss it in.) Furthermore, why aren’t there corresponding expressions using the colors orange and indigo? I know autistic children are sometimes called “Indigo children,” but I’ve yet to see a decent reason for why that is, other than perhaps the fact it might sound better than “autistic kids.”
It’s always fascinated me the things we say, often without really thinking too much about the how and why behind their provenance. Language is ever changing, ever evolving, so maybe in a few hundred years’ time, people will be purple when they’re sad, yellow when they’re angry, and indigo when they’re envious of someone/something.