Patent ID: 7559956

Claim:
A method for dyeing keratinous fibers comprising applying to the keratinous fibers a dyeing composition comprising at least one direct dye and at least one cationic hydrotrope of following formula (I): in which: X represents the CH or N + R 6 group with R 6 representing a linear or branched C 1 -C 10 alkyl radical; R 1 represents: a hydrogen atom or a linear or branched C 1 -C 10 alkyl radical, if X represents N + R 6 , or a (CH 2 ) n N + R 3 R 4 R 5 radical with R 3 , R 4 and R 5 , which are identical or different, representing a linear or branched C 1 -C 10 alkyl radical and n representing an integer between 0 and 12, if X represents CH; R 2 represents a linear or branched C1-C4 alkyl radical; and p has the value 0 or 1; wherein the electrical neutrality of the compound is provided by a cosmetically acceptable anion or a mixture of cosmetically acceptable anions, and wherein the dyeing composition does not comprise benzyltrimethyammonium salt or benzyltriethylammonium salt.