Observed and synthetic photometric variations of M-type Miras (and one C-type Mira RU Vir, which is included for illustration purposes). Top panels: photometric variations for the sample of observed targets, derived from sine fits of light-curves (see text in Sect. 5 for details). Middle panels: photometric variations for the dynamical models in set D. Bottom panels: photometric variations for the dynamical models in set D, with colors calculated from sine fits of the light-curves, same as for the observational data in the top panels. The right panels show the same content, zoomed in and centered on the color loops. For comparison, we also show the observational data of Fig. 4.