If your blonde or light-colored hair turns green in the pool, don't blame chlorine. Many people think chlorine is at fault when oxidized metal particles, such as copper and iron, are the real culprits. You don't need to suffer from grassy-colored hair for the whole swimming season, though. A combination of special shampoo and natural remedies will break down the copper and let your real hair color shine through.
Rinse your hair with lukewarm water from the shower when you're done swimming. This washes away the pool water, so it has less of a chance to turn your hair green.
Wash your hair with a shampoo that's formulated for swimmers. The shampoo should contain EDTA or chelating ingredients that break down and remove metals in your hair. Stop using swimmer's shampoo once the green hue disappears -- too much of this product can be harsh for your hair.
Pour 1/2 cup of white vinegar, tomato juice or lemon juice over your hair after swimming. Work it through your hair with a wide-tooth comb, wait for 10 minutes and then rinse out in the shower. Vinegar, tomato and lemon juice are all very acidic, and they'll remove copper oxides from hair naturally.
Wear a swim cap on your head when swimming. This shields your hair from the harsh chemicals in pool water. Before getting in the water, ensure that you've tucked all your hair completely underneath the cap.
Apply a silicone-polymer conditioner to hair before swimming. This helps prevent copper particles from clinging to hair. A dab of olive or coconut oil will also work.
Get a bleaching treatment at your salon if the green color won't go away. Opt for fast-acting bleach treatments so the chemicals won't damage your hair.