(z − K) vs. (g − K) for GCs of NGC 4486 and NGC 4649, indicated by different symbols and with error bars in the bottom panel. Note the wavy feature the data presents around (z − K) ~ 2 and (g − K) ~ 3.2. Upper panel: a running median on the data points; middle panel: 14 Gyr SpOT-Teramo and YEPS SSPs with a realistic treatment of the HB morphology (Raimondo et al. 2005; Yoon et al. 2006; Yoon et al. 2011a,b); Bottom panel: Maraston (2005) with blue and red HB at the lowest metallicities and Padova08 14 Gyr SSPs. See Fig. 16 of Chies-Santos et al. (2011b) for a (g − K) vs. (g − z) plot.