On hair color

"Do you think there is a difference between blondes and brunettes?" asked Bertlef, visibly skeptical about Dr. Skerta's experience with women.
"You bet!" said Dr. Skerta. "Blonde hair and black hair are the two poles of human nature. Black hair signifies virility, courage, frankness, activity, while blonde hair symbolizes femininity, tenderness, weakness, and passivity. Therefore a blonde is in fact doubly a woman. A princess can only be blonde. That's also why, to be as feminine as possible, women dye their hair yellow but never black."
"I'm curious about how pigments exercise their influence over the human soul", said Bertlef doubtfully.
"It's not a matter of pigments. A blonde unconsciously adapts herself to her hair. Especially if the blonde is a brunette who dies her hair yellow. She tries to be faithful to her hair color and behaves like a fragile creature, a shallow doll, she demands tenderness and service, courtesy and alimony, she's incapable of doing anything for herself, all refinement on the outside and coarseness on the inside. If black hair became a universal fashion, life in this world would clearly be better. It would be the most useful social reform ever achieved."

Milan Kundera, Farewell Waltz