Description Now get double the strength for fighting brassiness and fading with the Osmo No Yellow Duo shampoo and mask set. Containing extreme super-violet pigments, this sulphate free mixture is specifically formulated to target unwanted yellows in lightened, greying and bleached hair. Perfect for both natural and synthetic hair, the results leave blonde shades more balanced than before as radiant silver and ashy tones replace dull and tired brassiness. Contain extreme super-violet pigments Replaces unwanted yellow tones with silver and ashy shades Sulphate free formula Works on natural and synthetic hair. Shampoo: Apply directly to wet hair, massage well and leave for approximately 1-5 minutes. Rinse thoroughly and repeat if necessary. For best results, follow with OSMO Silverising Violet Mask. Mask: Apply to towel-dried hair, concentrating on the mid lengths to ends. Leave for approximately 3-5 minutes before rinsing thoroughly. Adding heat will intensify the treatment.