A color print painted with different colors C.sub.i (i = 1, 2 . . . n) is scanned by a color scanner along a plurality of successive line paths to generate a set of electrical signals each representing the intensity of the spectral components of the light reflected from an elemental area of the print. A macroscopic color separator is provided to generate a set of electrical signals each representing the average spectral intensities per unit area of the print. A data processor is used to compute the probability P(C.sub.i) from the data obtained from the macroscopic color separator and a set of mean spectral intensities exhibited by the color samples with which the print is painted by artisans. In accordance with the Bayes' Rule, the processor then executes computation of the product of P(C.sub.i) and the conditional probability of occurrence of elemental color spectral intensities given that the elemental area being scanned belongs to a particular color sample, using the data received from the color scanner as it scans the print.