What is the reason for giving two craps about the whole blonde v. brunette v. redhead battle?

Does anyone know when the competition between hair colors (for the most part for women) began and why? imo, it’s truly ridiculous, obviously, but what is the reason behind it, what is the social purpose? is it to get women to be competitive with each other and therefore unable to see how pointless this ‘battle of the colors’ is…why the whole ‘blondes have more fun’ ‘brunettes are smarter’ ‘redheads are hot in bed’ situation?