Dyestuff of the formula (Ia), (Ib), (Ic), (Id), (Ie) or (If) wherein D is a group of the formulae (IIa), (IIb), (IIc), (IId) or (IIe); wherein T 1, T 2 and T 3 are, independently, hydrogen, halogen or nitro; T 4 is hydrogen, halogen, cyano or nitro; wherein at least one of T 1, T 2, T 3 and T 4 is not hydrogen; wherein T 5 is hydrogen or halogen; and T 6 is hydrogen -SO 2 CH 3, -SCN or nitro; wherein at least one of T 5 and T 6 is not hydrogen; wherein T 7 is nitro, -CHO or a group of the formula wherein T 10 is -H, halogen, nitro and cyano; T 8 is hydrogen or halogen; and T 9 is nitro, cyano, -COCH 3 or -COOT 10, wherein T 10 is (C 1 -C 4)-alkyl; R 1 is (C 1 -C 4)-alkyl; R 2 is unsubstituted (C 1 -C 6)-alkyl, benzyl or phenylethyl; and n is 0, 1 or 2; or wherein T 3' is bromo or chloro; and R 2' is unsubstituted (C 1 -C 6)-alkyl, substituted (C 1 -C 6)-alkyl, benzyl or phenylethyl; or wherein D is a group of the formulae (IIa), (IIb), (IIc), (IId) or (IIe) as herein above defined, R 1 is hydrogen, (C 1 -C 4)-alkyl or -NCOR 6, where R 6 is (C 1 -C 4)-alkyl or phenyl; R 2 is as herein above defined; and R 3 is hydrogen and R 4 is methyl or R 3 is methyl and R 4 is hydrogen; or wherein D is a group of the formulae (IIa), (IIb), (IIc), (IId) or (IIe) as herein above defined, R 1' is as herein above defined; R 2' is as herein above defined; and R 5 is methyl or phenyl; or wherein D is a group of the formulae (IIa), (IIb), (IIc), (IId) or (IIe) as herein above defined, R 2 is as defined above; R 6 is (C 1 -C 4)-alkyl or phenyl; R 7 is chloro, methoxy or ethoxy; and n is 0, 1 or 2; or wherein R 2' is as herein above defined; R 8 is nitro; and n is 0, 1 or 2, with the proviso that R 2 is unsubstituted (C 1 -C 6)-alkyl if R 1 is methyl and n=0. D is a group of the formulae (IIa), (IIb), (IIc), (IId) or (IIe); wherein T 1, T 2 and T 3 are, independently, hydrogen, halogen or nitro; T 4 is hydrogen, halogen, cyano or nitro; wherein at least one of T 1, T 2, T 3 and T 4 is not hydrogen; wherein T 5 is hydrogen or halogen; and T 6 is hydrogen -SO 2 CH 3, -SCN or nitro; wherein at least one of T 5 and T 6 is not hydrogen; wherein T 7 is nitro, -CHO or a group of the formula wherein T 10 is -H, halogen, nitro and cyano; T 8 is hydrogen or halogen; and T 9 is nitro, cyano, -COCH 3 or -COOT 10, wherein T 10 is (C 1 -C 4)-alkyl; T 1, T 2 and T 3 are, independently, hydrogen, halogen or nitro; T 4 is hydrogen, halogen, cyano or nitro; T 5 is hydrogen or halogen; and T 6 is hydrogen -SO 2 CH 3, -SCN or nitro; T 7 is nitro, -CHO or a group of the formula T 8 is hydrogen or halogen; and T 9 is nitro, cyano, -COCH 3 or -COOT 10, wherein T 10 is (C 1 -C 4)-alkyl; R 1 is (C 1 -C 4)-alkyl; R 2 is unsubstituted (C 1 -C 6)-alkyl, benzyl or phenylethyl; and n is 0, 1 or 2; or wherein T 3' is bromo or chloro; and R 2' is unsubstituted (C 1 -C 6)-alkyl, substituted (C 1 -C 6)-alkyl, benzyl or phenylethyl; or wherein D is a group of the formulae (IIa), (IIb), (IIc), (IId) or (IIe) as herein above defined, R 1 is hydrogen, (C 1 -C 4)-alkyl or -NCOR 6, where R 6 is (C 1 -C 4)-alkyl or phenyl; R 2 is as herein above defined; and R 3 is hydrogen and R 4 is methyl or R 3 is methyl and R 4 is hydrogen; or wherein D is a group of the formulae (IIa), (IIb), (IIc), (IId) or (IIe) as herein above defined, R 1' is as herein above defined; R 2' is as herein above defined; and R 5 is methyl or phenyl; or wherein D is a group of the formulae (IIa), (IIb), (IIc), (IId) or (IIe) as herein above defined, R 2 is as defined above; R 6 is (C 1 -C 4)-alkyl or phenyl; R 7 is chloro, methoxy or ethoxy; and n is 0, 1 or 2; or wherein R 2' is as herein above defined; R 8 is nitro; and n is 0, 1 or 2, with the proviso that R 2 is unsubstituted (C 1 -C 6)-alkyl if R 1 is methyl and n=0. T 3' is bromo or chloro; and R 2' is unsubstituted (C 1 -C 6)-alkyl, substituted (C 1 -C 6)-alkyl, benzyl or phenylethyl; or D is a group of the formulae (IIa), (IIb), (IIc), (IId) or (IIe) as herein above defined, R 1 is hydrogen, (C 1 -C 4)-alkyl or -NCOR 6, where R 6 is (C 1 -C 4)-alkyl or phenyl; R 2 is as herein above defined; and R 3 is hydrogen and R 4 is methyl or R 3 is methyl and R 4 is hydrogen; or D is a group of the formulae (IIa), (IIb), (IIc), (IId) or (IIe) as herein above defined, R 1' is as herein above defined; R 2' is as herein above defined; and R 5 is methyl or phenyl; or D is a group of the formulae (IIa), (IIb), (IIc), (IId) or (IIe) as herein above defined, R 2 is as defined above; R 6 is (C 1 -C 4)-alkyl or phenyl; R 7 is chloro, methoxy or ethoxy; and n is 0, 1 or 2; or R 2' is as herein above defined; R 8 is nitro; and n is 0, 1 or 2,