OK, it's time to get something straight right off the bat. The chlorine in pools isn't what is causing your hair to turn green; it's the copper in the water that's making you look like you've just been slimed.

Chlorine is a chemical that kills germs, and when mixed with the natural copper in the water, it can turn dark blonde hair yellow, make highlights brassy, or turn light blonde hair green. Even if your hair isn't light or chemically treated, chlorine can dry it out. Below are a few quick and easy precautions you can take to protect your hair's texture and color.

• Before you get into the pool, rinse your hair with water from the shower or the tap and apply a conditioner to help coat your hair. This will act as a shield against the damaging chemical/metal mixture.
• If possible, don't stay in the pool for more than a few hours. If you are planning to swim for an extended period of time, then it's a good idea to wear a swim cap.
• As soon as you get out of the pool, shampoo and condition your hair immediately. A great suggestion is Swimmer's Normalizing Conditioner [1] and Swimmer's Normalizing Shampoo [2] ($7.70-$7.98 each) from Aubrey Organics. Work the shampoo into your hair, rinse well and repeat the process for optimal results.
• Deep-condition more regularly to avoid brittleness and breakage. Shiny, hydrated, healthy hair is less likely to be affected.

Source [3]