SYSTEM 4 - COLOURED HAIR - FOR PROGRESSIVE THINNING HAIR. Prepare the scalp and hair for a complete hair thickening treatment with Nioxin’s 3-part System 4 Cleanser for Colored Hair with Progressed Thinning. Thanks to its Pro-Color Shield technology, this professional hair product helps remove sebum, fatty acids and other environmental residue from the scalp and hair. Nioxin’s derma-purifying shampoo deeply cleanses the scalp and provides thicker, fuller-looking hair. Nioxin’s cleanser is the first step of a 3-part Nioxin regimen, designed to strengthen the hair and amplify hair structure.