  Electron-positron pair production in dynamically assisted two-color electric
fields is investigated for various polarizations. Momentum spectrum and number
density of the created pairs are examined carefully, in particular, the effects
of polarization and high harmonics of two-color fields are exhibited. For only
single strong field, the interference effects of momentum spectrum would vanish
when polarization is high, however, for the dynamical assisted two-color
fields, the interference effects would be more and more remarkable with
polarization. The multiple peaks of momentum spectrum in elliptic or/and
circular polarization are observed and explained. It is found that there exists
a strong nonlinear dependence of the number density on the high harmonics of
two-color fields, for example, the number density can be enhanced significantly
over $7-8$ orders when appropriate high harmonics is present. Another
interesting finding is that the polarization effect on number density is
gradually weaken as the high harmonics increases, however, a weak nonlinearity
relation appears again if the high harmonics exceeds a single-photon threshold.
