V vs. b − y CMD for measured stars distributed inside the star cluster’s radius (left panels) and their metallicity ([Fe/H]) distribution as a function of the V magnitude (right panels). The large filled red and blue circles represent stars used to compute the star cluster’s mean [Fe/H] value and those from a reference star field with [Fe/H] values similar to those of the star cluster’s stars, respectively (see text for details). Top and bottom panels: refer to NGC 1651 and 1795, respectively.