The present invention relates to pyrifone azo dyes of formula (1), wherein A is the radical of a diazo component of the benzene, naphthalene, diphenyl, azobenzene, thiophene, benzothiazole, benzoisothiazole, thiadiazole, indazole, benzotriazole, pyrazole, anthraquinone, naphttholic acid imide, chromone, phthalimide or diphenylene oxide series, R1 is hydrogen, unsubstituted or hydroxyl- or phenyl-substituted C1-C6alkyl, it being possible for the alkyl chain to be interrupted from C3 upwards by one or more oxygen atoms, or has the meanings of R2, R2 is a radical of formulae (2), (3), (4), (5), (6), or (7), wherein B is a bridging member, R4 is alkyl or aryl, R5 and R6 are each independently of the other alkyl, aryl or heteroaryl and A is as defined for formula (1), or R1 and R2 toghether with the nitrogen atom in NR1R2 form a heterocyclic ring, Y is cyano, —CONH2 or CH2SO3H, and n is an integer from 2 to 6, to a process for their preparation and to their use in the production coloured plastics or polymeric color particles.