Distributions of the fractional number of XMM-LSS X-ray sources as a function of their hardness ratio: (i) for the cases of all X-ray sources, X-ray sources with optical counterparts, X-ray sources with spectro-z or photo-z (bottom panel); (ii) ext and ptl objects according to our visual classification (middle panel); (iii) GALs and AGN/QSOs according to spectroscopy, SEDs and/or L_X criteria (top panel).We plot Poisson uncertainties only in the upper panel for clarity.