Distribution of model colours obtained from the sample of 10⁶ galaxies drawn from the PROSPECTOR-β model. The colours are obtained using mock apparent magnitudes in the KiDS-VIKING ugriZYJHK_s bands. We display the 16th, 50th, and 84th quantile values for each colour at the top of the corresponding 1D histogram. The dotted lines in each 1D histogram are the 16th and 84th quantile values. The 2D contours enclose the 68%, 95%, and 99% of the values.