The sensor device has a number of optoelectrical transducers (1), e.g. photodiodes, each of which is wavelength selective, for providing an electrical output signal fed to a respective measuring channel, containing a signal processing circuit (2,3,4). The measured signal values provided by the signal processing circuits are compared with reference values via a fuzzy-logic circuit (6), for allocating them to a greater number of signal channels (7). USE - For colour recognition system.