CMDs of fields SE1 (top-left), SE2 (top-right), SE3a (bottom-right), and SE3b (bottom-right). The boxes in the top-left panel display the location of RGB and RC stars in the diagrams. Ten Gyr isochrones from Marigo et al. (2008) at a metallicity of [M/H] = −0.4, −0.7, −1, −1.3 are overlaid on the top-right panel to give an indication of the expected metallicity range of the RGB population. Light blue and red tracks in field SE3a (bottom-left) correspond to a metallicity [M/H] = −0.7 and an age of 250 Myr, 1 Gyr, and 10 Gyr, while dark blue and purple tracks in field SE3b (bottom-right) indicate the same age range for a metallicity of [M/H] = −0.4.