Cationic dimeric dyes

The present invention relates to novel cationic dye of formula (1) and (1a) wherein A is an organic radical of formula (2) or (3) wherein R1 and R2 are each independently of the other unsubstituted or substituted C1-C14alkyl or an aryl radical, R3 is hydrogen, unsubstituted or substituted C1-C14alkyl, unsubstituted or substituted C1-C14alkoxy, cyan or halogenid, R4 is hydrogen, unsubstituted or substituted C1-C14alkyl or an aryl radical, and X- is an anion. Further, the present invention relates to compositions thereof, especially comprising other dyes, to processes for the preparation thereof and to the use thereof in the dyeing of organic material, such as keratin, wool, leather, silk, paper, cellulose or polyamides, and preferably human hair.