  We study the phase diagram of a chiral random matrix model with three quark
flavors at finite temperature and chemical potential, taking the chiral and
diquark condensates as independent order parameters. Fixing the ratio of the
coupling strengths in the quark-antiquark and quark-quark channels applying the
Fierz transformation, we find that the color-flavor locked (CFL) phase is
realized at large chemical potential, while the ordinary chirally-broken phase
appears in the region with small chemical potential. We investigate responses
of the phases by changing small quark masses in the cases with three equal-mass
flavors and with 2+1 flavors. In the case with three equal-mass flavors, we
find that the finite masses make the CFL phase transition line move to the
higher density region. In the case with 2+1 flavors, we find the two-flavor
color superconducting phase at the medium density region as a result of the
finite asymmetry between the flavors, as well as the CFL phase at higher
density region.
