J vs. J − H CM diagram for YSOs of the Sh2-90 complex. The PMS isochrones of 1 Myr from Siess et al. (2000) and Baraffe et al. (1998) are drawn in solid and dashed curved lines (black), respectively, for a distance of 2.0 kpc and zero reddening. The reddening vectors corresponding to 0.1, 0.15, 0.2, 0.5, 1, 3, and 4 M_⊙ are drawn in dotted slanting lines. The ZAMS (vertical dashed line in blue), along with the reddening vector (slanted line in blue) from the tip of the B0 star, is also shown. The average error in color is shown on the upper-right side of the figure.