Attention is given to the theoretical period-luminosity-color relations of stars evolving with mass loss that cover the upper part of the HRD, and pulsation periods are determined for the fundamental radial mode and first and second overtones. It is noted that the pulsation Q-terms present a minimum near T(eff) of 20,000 K, and that the Q-terms increase both for hot main sequence stars and cool and luminous red supergiants. A comparison of models with observations indicates that about 40 percent of the supergiants have periods which are in agreement with the fundamental mode of radial pulsation.