Color-magnitude diagrams of Gaia and 2MASS datasets. Targets from the SMC source catalog are shown as gray dots. The valid RSG candidates are shown as solid circles and are color-coded ranging from Rank −1 to 3. Three Rank 4 spectroscopic RSGs are shown as open triangles, while the other three Rank 4 CMD RSG candidates are shown as open stars. Two unselected spectroscopic RSGs are shown as open squares. The rest of Rank 4 and 5 targets from the main RSG sample are shown as open circles. Black contours represent the number density of the SMC source catalog. See text for details.