Seems luxurious but disappointing over time

At first I fell in love with this shampoo. The smell and the luxurious foam are wonderful. It is very conditioning for dry hair. But after about a month of use, my color is terribly faded, more so than with other shampoos. It is also limp and lifeless, dull and weighed down, as if there were a lot of buildup. I still have this but now I only use it the last week before I'm getting my color done because otherwise it fades too much. It is also very pricey, which I wouldn't mind if it were worth it, but I don't feel that it is worth the cost at all.