Someone who has, or thinks he has, a hair style that makes him appear rich. Usually the person is not rich, which is why he resorts to his hair to appear rich.
Eric: Man, I just cut my hair today.
Carl: Nice, looking sharp.
Eric: Yeah I know! People say I look rich and that I am a perfect 10. Rich in the hair!
When someone's hair is comically without texture, a guy that uses mathematical concepts and the golden ratio to make his hair attract the least bitches possible, combs his hair and makes it look like plastic, uses gel like it's free and normally does shitty haircuts that make his face even more horrendous than it is, normally happens to white rich boys who think they have the best haircut in a 5 mile radius
"Jack thinks he's rocking his new haircut and style but little does he know it's just rich boy hair"