US Patent No. 8,518,423 B2; Kao Corp., Tokyo, has patented a method for enhancing chroma of hair. It entails shampooing the hair with a water-based shampoo containing (A) anionic surfactant, (B) a water-insoluble modified silicone containing at least one of an amino group and a quaternary ammonium group in a molecule thereof, and (C) a water-soluble salt in an amount capable of allowing the B component to be present in a solubilized state. A water-based conditioner containing a higher alcohol having 12 to 28 carbon atoms and a cationic surfactant at a molar ratio of 1:1 to 10:1 is applied to the shampooed hair. The hair is then rinsed.
The anion of water-soluble salt (C) comprises an inorganic anion selected from the group consisting of hydrochlorides, sulfates, nitrates, phosphates and chlorates, or an organic anion selected from the group consisting of acetates, citrates, malates, lactates and oxalates.