CCDs of J–H/H–K_S, J–K_S/K_S– IRAC4, J–K_S/K_S–WISE3 and J–K_S/ K_S–WISE4 for the initial sample. An A_KS ∼0.5 mag reddening vector is shown in the diagram for reference (same below). The two populations of RSGs (brighter and fainter) seen in previous CMDs also appearing in J–K_S/ K_S–IRAC4 and J–K_S/K_S–WISE3 diagrams due to the higher sensitivity in IRAC4/WISE3 compared to WISE4 band, with fainter population is clumped around the infrared excess turning point and the brighter population is extended toward the red end of K_S–IRAC4/K_S–WISE3 color.