ALEXANDRIA, Va., June 19 -- United States Patent no. 12,329,838, issued on June 17, was assigned to The Procter & Gamble Co. (Cincinnati).
"Hair dye composition" was invented by Shufen Fan (Singapore), Mei Yi Tee (Singapore) and Pei Qi Lim (Singapore).
According to the abstract* released by the U.S. Patent & Trademark Office: "A tunable hair dye composition that includes at least two photochoromic dyes, each activatable by activating electromagnetic radiation and deactivatable by deactivating electromagnetic radiation. The composition can be applied to a target skin or hair surface and, when activated, impart a temporary color change to the skin or hair. Prior to activation, the photochromic dye is generally colorless. The intensity or sh...