The M(R) relationship for hybrid stars involving quark matter obeying the simple bag model equation of state, with various values of c and ρ_c, and ﹩m_{s}=180﹩ MeV and ﹩\Delta =0﹩. The line with filled circles is the M(R) relation for a pure nuclear APR star. The solid lines are for hybrid stars with homogeneous neutral APR and CFL phases; the dashed lines are for hybrid stars with mixed APR+CFL phases. We see that the maximum mass M_max is very sensitive to the perturbative correction c but not to the transition density or the occurrence of mixed phases. For ﹩c=0.3﹩, which is close to the value suggested in Fraga et al. (2001), ﹩M_{\mathrm{max}\,}\approx 1.9﹩ M_⊙.