Optical (dereddened) CMDs of the target galaxies, in order of increasing luminosity. The dominant feature of the CMDs is a prominent RGB, there being a small amount of luminous AGB stars above the TRGB (indicated by a red dashed line). Representative photometric errorbars are plotted at the left side of the CMDs. Green lines are stellar isochrones with a fixed age of 10 Gyr, and varying metallicity: [Fe/H]  =     −2.5,  −1.52, and  −1.1 (from the blue to the red side) for CenA-dE1; [Fe/H]  =     −2.5,  −1.08, and  − 0.4 for SGC1319.1-4216; [Fe/H]  =     −2.5,  −1.21, and  − 0.4 for ESO269-066 (see text for details).