Top: mass-loss rates vs. luminosity for SMC (left) and MW (right). The colour bar shows the T_eff. The grey triangles represent the upper limits, and the open circles indicate the RSGs with spectral classifications. The magenta points correspond to the prediction of the derived Ṁ(L,T_eff) relation. The dashed blue lines show the prescription from Beasor et al. (2020) for initial masses of 10 and 20 M_⊙ and the dash-dotted orange line is the one from de Jager et al. (1988). Middle: MAD of W1 band vs luminosity diagram for the SMC (left) and the MW (right). The colour bar shows the mass-loss rate. Bottom: mass-loss rates vs the effective temperature for the SMC (left) and the MW (right) indicating the luminosity with colour.