Here's an interesting sidelight on human-designed colour palettes. I tried running my
photo from "Primark and the Spectrum Suckers" through Colormind.
The photo is predominantly brown, and
every single palette Colormind made from it contained some kind of purple, not too different from the one on the left below.
Colormind, I explained in my post about it, extracts the main colours from a photo, produces random variations on them, and then sends these for scrutiny by a gatekeeper: a machine-learning program trained on palettes that Jack Qiao, Colormind's author, thought were good looking. I wonder whether Jack didn't use enough palettes to teach it that brown doesn't always have to go with purple. Google colour palette brown and you'll see that there are other choices.