The colour violet has the shortest wavelength on the visible spectrum (380-450 nm) and, given its high frequency, it has the most energy of any light that enters our eyeballs.
Violet—or its low class stand-in, purple—is a lavish, extravagant colour. Overblown writing is called purple prose. Overdressed musicians produce movies called Purple Rain. And people who think they’re better than us (i.e. royalty) use purple to reinforce that very rotten idea.
Most edible tubers can be purple. Beets are an obvious example. Despite our belief that carrots should be orange, that’s really a matter of marketing. Carrots would happily be purple if we let them. The same goes for potatoes.
If we fall down and hurt ourselves, a phenomenon called bruising turns our skin purple. And if our lover strangles us, we turn purple for pretty much the same reason (lack of oxygen in our blood).