Color-CaT and a selection of color–color diagrams for the HS sample (sel#1, full gray circles). Open circles mark GC candidates rejected by the adopted selection criteria. SPoT SSP models for [Fe/H]  =  −2.3 (pink), −1.3 (red), −0.7 (yellow), −0.3 (cyan), 0.0 (blue) and + 0.3 (green) dex are also shown. The age range is 2 ≤ t(Gyr) ≤ 14, at fixed metallicity younger ages have bluer color. Histograms, and nonparametric density estimates for histograms are also shown with arbitrary scale. (This figure is available in color in electronic form.)