My hairdresser suggested I use this product on my bleach blonde hair to eliminate some of the brassy yellow tones. I went out and bought the shampoo and conditioner w/o even thinking about reading some reviews first. Well, I washed and conditioned my hair with it, and I ended up with purple highlights! So not only did I spend $20 on the shampoo and conditioner, I now also have to spend money to have my hair recolored. What I don't understand is that it says right on the label "will not leave residue, no patch test required". All I have to say to that is yeah, ok. Thanks Clairol!