Field locus on the r versus g − r diagram (gray). The sequence traced by the clustered population, extracted as described in Sect. 3.2, is highlighted in green. The 1 Myr, 3 Myr, and 5 Myr model isochrones from Marigo et al. (2017), brought to a distance of 800 pc and reddened by an amount corresponding to A_V = 0.5 (typical A_V measured for sources in the clustered population), are overlaid on the diagram.