In the summer, most everyone goes swimming in the pool which is full of chlorine. When you jump into the pool, chlorine creates a chemical reaction with your hair. The reaction of the melanin pigments in your hair causes it to change color (not drastically). Chlorine also removes natural oils in the hair causes it to become frizzy and have less shine. Chlorine creates another chemical bond with the hair, which causes the ends of your hair to split. Alongside all of the bad chlorine does, you can buy hair products to put in your hair to attain the shiny look.