J–H vs. H–K_s diagram for the 2MASS stars with errors of magnitudes ≤0.05 mag found in the 15′ × 15′ box centered on IC 1805. We show the main sequence (MS, brown belt), red giant branch (RGB, orange belt), the intrinsic locus of red clump giants (RCG) with its reddening line, the reddening line corresponding to Q_JHKs = 0 and the intrinsic T Tauri line. The Herbig Ae/Be stars (the crosses below the T Tauri line) are marked with numbers from Table 1 or from Massey et al. (1995). The probable low-mass YSOs (above the T Tauri line) are the crosses marked with numbers from Table 2. The red giant with the highest reddening is marked by A (see text).