Years ago I found a simple 'natural' way to bring back dull, lifeless hair. Buy SwissKris - It is an herbal laxative. That's right, an herbal LAXATIVE. It's a tea that you boil and then when it is cool enough - pour it all over your hair and wrap your head in a towel and let it set for an hour or so. It really makes your hair shine.I found it really helps dark hair look good. If I remember correctly, the directions for this is in the package.

As far as a good shampoo for color-treated hair...inexpensive L'Oreal Color VIVE Shampoo for color-treated hair.

If the hair is damaged then a good haircut is the only thing that will start you out right.