Features: covers all grey, even the most elusive greys, at 100%. Three lines of defense For up to eight weeks, color with anti-brass technology protects both during and after coloring. Smoothes the hair with a new gentle shampoo. Selecting the ideal shade for you: The outcome of your hair color will differ based on your natural color. Picking the lighter shade is always advised when choosing between two. The color outcome Color will seem paler on grey hair than it does on non-grey hair. 48 hours prior to use, do an allergy test.