The effects of primary coma and astigmatism in the colour distribution of the polychromatic point-spread function are studied for diverse values of these aberrations. Dispersive wave-aberration coefficients, more significant in the chromaticity distribution than the constant ones, have also been studied in this paper. Moreover, the relative influence of the aberrations in the colour of the off-axis image is shown, so that the colour distribution for every optical system can be predicted from its aberrations. Finally the tolerances for the monochromatic aberrations when the illuminance reaches 0·8 and their corresponding colour distributions are obtained. The influence of the spectral distribution of the source is shown simultaneously.