So, I have Marvel Storm grey hair. My hair has been bleached so many times that my ends are near clear platinum and if I don't use the right shampoos, it turns into straight up straw that is impossible to comb through and painfully rough to touch. My hairstylist recommended me the Joico Color Endurance Violet shampoo and conditioner as its sulfate free and super gentle on my hair and at the same time helps me maintain my grey without getting brassy. This is honestly one of the best purple shampoos I've used as it keeps my hair untangled, smooth, and tamed. Not to mention it smells great! I've used many purple shampoo brands such as the Clairol Shimmering Lights, but those dry out my hair extensively and cause a lot of breakage + don't even keep my hair grey for long. My last toning session as in January, so I'm super surprised that even after 4 months, my hair is still grey as it usually fades with other shampoo!