[2020] Ok, so what's up with the color palette in this game?

I'm just intrigued, maybe even obsessed, by the uniqueness of it. It's not like anything I've seen before. There was absolutely some kind of conscious choice that went into designing the color theming in this game, but I can't actually figure out what it was. It's highly out of the ordinary and stands out - I know a screenshot or asset or character is a TemTem - rather than being from something else - just by looking at the color combinations.

Has there been any official writeup on the color palette choices for this game? What principles were they using? Anything at all? I want to know what's going on here.