Colours, magnitudes, and theoretical isochrones. Colour-magnitude diagram (CMD) for sources in Fig. 6 (left panel), full sample of 15 681 sources (in grey) and the one of 393 sources (in black). Five isochrones of ages 1 Myr (in violet), 5 Myr (in purple), 10 Myr (in blue), 25 Myr (in cyan), and 50 Myr (in green), and solar metallicity are plotted as a reference (see the text for details). CMD for the candidates in Tables 2 (in red), 4 (in blue), and 6 (in brown) with error bars (right panel).