A recent article published in Psychology today (also here)  it was discussed whether men prefer blonde or brunette. There is a Marilyn Monroe film there too that we all know and love and Dr. Lisa Walker, Sociology Department Chair at the University of North Carolina said that hair color “absolutely” plays a role in the way people are treated and claimed that numerous studies had shown that blonde women were paid higher salaries than other women. “Most people would tell you, if asked, that it doesn’t matter what your hair color is. What style your hair is in. They would say whatever is best for your face,” explained Walker. “But from a very young age these stereotypes appear. In cartoons and children’s programming, we see the way women are portrayed based on their hair. The associations continue through childhood into adulthood.”[48]
I had a lot of fun researching this and discovered a sexually charged Hammer forgotten classic from 1967 called Prehistoric Women watch the trailer here which is basically about a  Queen & tribe of brunette women being served by their blonde slaves, it’s hilarious but there is some fantastic 60’s makeup going on there so worth a watch for that alone!