Patent No. US 7,416,567 B2
A cosmetic composition for keratinous substrates with triarylmethane compounds has been patented by L'Oréal, Paris. It contains at least one triarylmethane dye molecule chosen from polymeric triarylmethane dye molecules, copolymeric triarylmethane dye molecules, oligomeric triarylmethane dye molecules, and mixtures thereof; at least one film forming agent; and at least one solvent. The cosmetic composition is put in contact with the keratinous substrate to form a treated keratinous substrate; and the treated keratinous substrate is irradiated with a flash of light.