Distribution of the RSG effective temperatures () depending on host galaxy metallicity ([Fe/H]). We add sample RSGs from the LMC and SMC (Davies et al. 2013), and three well-studied RSGs in IC 1613 from Tautvaišienė et al. (2007). The horizontal lines correspond to possible effective temperatures for RSGs with initial masses of 8−40 M_⊙ for each available metallicity in the PARSEC evolutionary tracks (Bressan et al. 2012). The range of possible theoretical luminosities for a given range of temperatures is presented in the color bar.