Luminosity–hardness evolution of the subset of 59 variable XRB and ULX. HR67 is the hardness ratio between 0.2 − 2 and 2 − 12 keV bands. All detections having HR67_err < 0.25 are shown. To ease visualisation, for each source, the correlation, anti-correlation, or absence of correlation between L_{X, detection} and HR67 are highlighted at the bottom of the graph by the “+”, “−” and “=” signs, respectively.