Shampoo for Colored Hair
A: When you are dealing with color-treated hair, you want to use a shampoo that is gentle. This specifically means one that won't overly strip the hair. Most daily use shampoos are fine for this purpose. The only time you really have to worry is in hair color treatments that are prone to fading, such as with some red hair color formulas.
You should generally use the shampoo and conditioner that you prefer. Base your decisions on which products make your hair look and feel best. There are many products on the market now that boast claims of "extending the life of your hair color" but the claims of these products should be taken with a measure of skepticism. The formulations are based on sound theory, but the actual results are less significant than what may be claimed.
The bigger concern in selecting products for hair that is color treated is the condition of the hair after the color service. In color services that included a lightening stage as well as a toner stage, there may be some damage to the hair and increased porosity. A good acid-balanced conditioner will help to contract the swollen hair shaft and compact the cuticle layer, which will help to seal in the color and restore a look of healthy shine. Damage can also occur to hair that is frequently colored and re-colored using non-lightening hair color formulas.
Remember that damage done to the hair is cumulative. Think of it this way: the fibers of the hair on your hair are like the fibers that make up the fabric of the clothing you wear. Daily wear and washing, ironing, etc. gradually wear down the fibers and the clothes wear out. You can't buy any product that will miraculously "make the clothing new" again.
You can, however, use products that will help to protect your clothes and keep them looking new longer. This is similar to the way hair works. The fibers of the hair are no longer alive and cannot "heal", but you can take proper care of your hair and minimize the daily accumulation of damage to the hair and keep it looking healthy as long as possible.
©Hairfinder.com
See also:
How to dye hair
Are shampoos for specific hair types worth their money?
How to take care of colored and chemically treated hair
How to prevent that colored hair fades too fast