https://peakd.com/@edicted/brain-color-hacks
I actually wrote this post on the psychological effects of color.
Red is particularly relevant because it elicits native aggression.
The main idea being that when we see things like blood it triggers a fight/flight response.
The other really interesting thing I learned was that professional sports teams aren't allowed to paint the locker room of another team a different color. Before this rule was enacted someone figured out if you paint the walls Pepto Bismol pink it has a calming or even demoralizing effect.