Colored T_eff plots in different bands from the NTT sample (filled circles) and the SSO 2.3 m sample (open circles). Spectral types are also indicated. The predictions from BT-Settl (solid line), NextGen (dotted line), and AMES-Dusty (dash-dotted) for solar metallicities are over plotted. Theoretical masses in solar mass are indicated. Predictions from other authors are shown for comparison when available.