With normal use, the purple shampoo will not impart dye on your hair permanently; however, sometimes with overuse or when hair is extremely damaged or is of the lightest blonde shades, a purple hue will be imparted on the hair. We recommend that you only use this product no more than three times per week and on the other days use your normal daily shampoo and conditioner. The colour is not permanent and if you discontinue use, it should fade away with normal washings.