Same as Fig. 3, for giant stars in NGC 6791. The metallicities are taken from the following publications: Worthey & Jowett (2003); Friel et al. (2002); Geisler et al. (2012); Carraro et al. (2006); and Gratton et al. (2006). Data for the following stars are shown (reference T_eff in K, star number from Stetson et al. 2003): (3860, 8904); (3930, 7972); (3940, 8266); (3970, 5342); (4000, 11 814); (4090, 8563); (4120, 10 898); (4130, 8988); (4190, 4952); (4200, 6288); (4400, 3369); (4410, 4715); (4420, 7922); (4430, 2723); (4440, 9462); (4450, 10 806); (4460, 8082); and (4470, 9316). The bars on the right indicate minimum and maximum uncertainties for the individual [Fe/H] values quoted in the publications.