Patent ID: 6843256

Claim:
A method of colouring keratin-containing fibres that comprises treating the fibres with a dye of formula wherein Y 1 and Y 2 are each independently of the other hydrogen, unsubstituted or substituted C 1 -C 4 -alkyl, or halogen, R 1 and R 2 are each independently of the other hydrogen or unsubstituted or substituted C 1 -C 4 alkyl, R 3 and R 4 are each independently of the other hydrogen, unsubstituted or substituted C 1 -C 4 -alkyl, C 1 -C 4 alkoxy or halogen, R 5 is hydrogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy or halogen, X is C 1 -C 12 alkoxy or a group of formula —N(R 6 )—CO—R 7 , wherein R 6 is hydrogen or C 1 -C 4 alkyl and R 7 is hydrogen, C 1 -C 4 alkyl or —NH 2 and A − is an anion, With a proviso that Y 1 and Y 2 are each independently of the other not hydrogen atom when R 3 and R 4 are each independently of the other methoxy group.