The aim of this work was to find the lowest concentrations of non-mineral blue dyes and pigments using infrared spectroscopy with Fourier transformation, Raman spectroscopy and mass spectrometry based on laser desorption/ionisation-time of flight, in fresh and artificially aged model colour layers, for which the detection of indigo, Prussian blue and copper phthalocyanine in differently prepared samples could be reliably performed. This research was motivated by the fact that the presence of a particular blue dye allows at least approximate dating of artworks and therefore may be conducive to determining their authenticity, as is shown on a Czech cubist painting in this paper.