The present invention relates to a cyanated perylene compound of the formula I in which one of the Z substituents and one of the Z* substituents are cyano and the other Z substituent and the other Z* substituent are each independently CO2R9, CONR10R11, optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl or C6-C14-aryl, where R9, R10 and R11 are each as defined in the claims; and mixtures thereof. The present invention further relates to a composition comprising a cyanated perylene compound of the formula I or mixtures thereof and to a process for preparation thereof; to color converters comprising at least one polymer as matrix material and at least one cyanated perylene compound or mixtures thereof or a composition comprising at least one cyanated perylene compound or mixtures thereof as fluorescent dye; to the use of these color converters and to lighting devices comprising at least one LED and at least one color converter.