  The phase diagram of a two-flavor Polyakov loop Nambu-Jona-Lasinio model is
analyzed imposing the constraint of color charge neutrality. Main effects of
this constraint are a shrinking of the chiral symmetry breaking (chiSB) domain
in the T-mu plane, a shift of the critical point to lower temperatures and a
coexistence of chiSB and two-flavor superconducting phases. The effects can be
understood in view of the presence of a nonvanishing color chemical potential
mu_8, which is necessary to compensate the color charge density rho_8 induced
by the nonvanishing Polyakov-loop mean field phi_3.
