This concept as described reminded me immediately of a book I read as a teenager, called Divided Kingdom by Rupert Thomson: https://en.wikipedia.org/wiki/Divided_Kingdom
It is about the country being broken up into four sectors based on the four humors: red, green, yellow, and blue. Scanning through some descriptions of Surrounded by Idiots, the similarities are uncanny. I thought the whole four-humors thing and its derivatives have been definitively debunked for a very long time, how did this book not get laughed out of the gates?
[0] Parts that made me pause: 'Around the same time, qualified psychologists began reporting how clients were considering leaving their partners because, “I can’t possibly live with a yellow person”...'; '...they had been tested at the Human Resources department only to be told they needed to move to another team because their “colour combination”...'; '...A teenage girl comes home and tells her mother, with an air of resignation, “mum, I’m a green.” She had been tested by her school counsellor...'