Figure 3: Integrated (H-K) colours of a sample of Magellanic Cloud clusters (Persson et al. 1983, ApJ, 266, 105) as a function of their age. The individual ages have been obtained using the age calibration given in Eq.2 of Ferraro et al. (1995, MNRAS, 272, 391); metallicities are assigned consistently with the SWB class-metallicity relationship used by Gonzalez et al. (2004). Appropriate theoretical integrated colour predictions (from isochrones including convective core overshooting) are also displayed.