Left panel: comparison between the observed CMDs for Fields 4 (upper panel) and 1 (lower panel) and scaled solar theoretical isochrones for different assumptions about age and metallicity. Lines on the RGB are for [Fe/H] = −1.27, 12 Gyr (continuous line), [Fe/H] = −0.96, 6 Gyr (dashed line), and [Fe/H] = −2.27, 12 Gyr (dotted line). Lines on the MS show two isochrones, respectively with [Fe/H] = −1.27 and age 11 Myr (solid line) and with [Fe/H] = −0.35 and age 30 Myr (dashed-dot-dot-dot line). Right panel: comparison between core He-burning stars in the CMDs of Fields 1 and 4 and a theoretical ZAHB (with mass range between 0.6 M_⊙ and 2.8 M_⊙, in order to include both low-mass HB models and RC ones) for two different metallicities, [Fe/H] = −0.96, and -1.49 (dashed and continuous line respectively). All the shown isochrones have been retrieved from the BaSTI archive except the one corresponding to [Fe/H] = −1.27 and age of 11 Myr, which has been computed for the present work.