The present invention relates to a process for the preparation of a mixture comprising at least two structurally different diketopyrrolopyrrole pigments of formula (1) wherein A.sub.1 and A.sub.2 are each independently of the other an aromatic or heteroaromatic radical, by reacting a succinic acid ester with at least one unsubstituted or substituted aromatic or heteroaromatic nitrile, which process comprises carrying out the reaction in the presence of at least one compound of formula (2) wherein A is an aromatic or heteroaromatic radical, R.sub.3 is hydrogen, halogen, methyl, methoxy, --CF.sub.3 or --CN, R.sub.4 is a linear or, from C.sub.3 upwards, optionally branched C.sub.1-C3.sub.0alkyl, C.sub.6-C.sub.10aryl or C.sub.6-C2.sub.4aralkyl radical, X is --S--, --O--, --CR.sub.5R.sub.5'--, --COO--, --CONR.sub.5--, --SO--, SO.sub.2--, --SO.sub.2NR.sub.5-- or --NR.sub.5-- and R.sub.5 and R.sub.5' are each independently of the other hydrogen or a linear or, from C.sub.3 upwards, optionally branched C.sub.1-C.sub.30alkyl, C.sub.6-C.sub.10aryl or C.sub.6-C.sub.24aralkyl radical, to the use of such a mixture in the coloring of organic material and in cosmetics, and also to novel diketopyrrolopyrrole pigment mixtures ##STR00001##