There are several steps you can take to prevent white hair discoloration. White hair turning yellow may be an age-related pigment change, but it also could be due to various external influences, such as the environment or condition of the water pipes. Gray and white hair do not contain any of the pigment that colors younger hair, so it tends to show colors of foreign materials picked up from water -- from the shower or swimming pool, for example -- or even from pollutants in the air. Metals such as copper are the most common causes of hair discoloration. Smoking can cause both the hair and fingernails to yellow, which can also be due to beauty supplies like shampoos, conditioners or other hair care products.
Try a hair care product like "No Deposit" shampoo, which will remove smoke and any product buildup that might be causing the discoloration.
You may also be able to correct the problem by using a hair care product like a shampoo or rinse that will subtly neutralize the off tones and restore a silver, gray or white tone.
Look for a gentle natural blue or violet rinse to use on your hair, which can brighten silver hair and take the brassiness out of colored hair.
Damage may also be caused by perming your hair, or the use of excessive chemicals like hair dyes. The cuticle of the hair shafts can be damaged and when they come in contact with mineral deposits, it can cause redness and rusty-looking hair.
Iron and rust deposits are fairly common, and can come from well water, water from rusty pipes or just very hard water. To treat discoloration from iron deposits, use a mixture of vinegar with some cream of tartar. Leave it for about 10 minutes and rinse with cool water. Lemon juice is also handy for this type of discoloration. Apply it to your hair, leave for 10 to 15 minutes and rinse thoroughly.
Mix baking soda in with your regular shampoo. Wash your hair and rinse with plain water. Use a conditioner.
If you choose a blue or violet rinse, follow directions carefully so you don't end up with a blue cast to your hair.
Utilize shampoos containing chelating agents such as sodium EDTA or D-Penicillamine.
The problem will continue unless preventive measures are undertaken.
You may need a water purifier for your home, or even replumb the water pipes.
Do not use excessive chemicals of any kind.
Dry your hair quickly as the reaction between iron and water creates rust.
Green hair is an unusual condition due to deposition of copper from water. This condition is seen in subjects with natural or bleached blond hairs or in subjects with white or gray hair.