[theoh]

I'm in the field (recent MA in art).

Colour theory, beyond the important concept of complementaries, is very unscientific. I'm not aware of any credible, rigorous scientific findings about colour and emotion that are actually used by artists. (I'm not saying that no credible research will ever exist: see links here https://designshack.net/articles/graphics/the-science-behind... )

Painters (etc.) choose and apply colour in an intuitive way. Some artists are known as "colourists" for their skill in orchestrating colour effects. The way to learn is to look at that kind of work and absorb the aesthetic.

[BadassFractal]

That's been my experience as well when trying to learn from artists who do this. As you said, they most often will simply follow their intuition built over many years of trying different things and learning what seems to cause what kind of result. It'd certainly be neat to shortcut that process, I don't think there's anything magical about it, it's just that people have likely never had to bother.