Color–magnitude distribution of all stars identified as M giants. Left: G-band absolute magnitude as a function of (Gbp − Grp)0 color. Right: dereddened (J − K)0 vs. (W1 − W2)0 color–color diagram. Note that all dots are M giant candidates that were classified through LAMOST spectra. We use colors to distinguish misidentified stars, which include early-type stars (green), M dwarfs (red), and white dwarf binaries (orange).