Nexxus Color Assure Sulfate-Free Daily Shampoo 33.8 oz. Nexxus Color Assure Shampoo for color-treated hair has been specially formulated to help extend the color vibrancy of color-treated hair for longer. Using our exclusive PROTEINFUSION blend this sulfate-free shampoo for color treated hair helps replenish nutrients to help enhance color vibrancy. For best use apply this silicone free shampoo with pump to wet hair. Later rinse and follow with Nexxus Color Assure Conditioner. Nexxus scientists used Proteomics studies to examine hair damage at the molecular level and found that the main cause of color loss and dullness is hair coloration. For adult use.