Luminosities of massive stars with A_Ks> 0.8 mag are plotted versus their effective temperatures. Stellar tracks for stars of 9, 15, 25, and 40 M_⊙, based on the new rotating Geneva models with a solar metallicity, are shown with dotted and dashed lines; darker curves show the corresponding isochrones at 32, 20, 8, 5, and 3 Myr (Ekström et al. 2012). The positions of Of_K+ stars are marked by asterisks, the cLBV by a plus sign, the WR number 39 in Mauerhan et al. (2011) by a diamond symbol, other OB stars by filled triangles, and RSGs and cRSGc by empty triangles.