  From a theoretical study based on nonlinear, nonlocal and time-dependent
convective pulsating models at varying mass and chemical composition, we
present the predicted Period-Luminosity, Period-Color, Color-Color and
Period-Luminosity-Color relations in the BVRIJK bands for Classical Cepheids.
All the theoretical relations are, in various degrees, metallicity dependent
and the comparison with observed data for MC and Galactic Cepheids show a fair
agreement which supports the validity of the pulsating models.
