Near-infrared color-color diagram for the PMS stars we investigated. Circles denote the PMS stars, with the color indicating the amount of veiling measured in 8798–8802 and 8813–8819 Å. The dash- dotted lines represent the linear least-squares fit to the intrinsic color of the CTTSs (Meyer et al. 1997). Intrinsic colors for main-sequence stars (solid line) and giant stars (dashed line) are from Bessell & Brett (1988). B.G. stands for background star. The arrow and dotted lines show the interstellar reddening vector from Cohen et al. (1981).