  We derive and analyze the Bethe-Salpeter equations for spin zero diquarks in
the color superconducting phase of cold dense QCD with two massless flavors.
The spectrum of diquarks contains an infinite number of massive excitations and
five (nearly) massless pseudoscalars. The former are singlets while the latter
include a doublet, an antidoublet and a singlet with respect to the unbroken
$SU(2)_{c}$. Because of an approximate parity doubling at large chemical
potential, all massive states come in pairs. The decay constants, as well as
the velocities of the (nearly) massless pseudoscalars are derived. The
different role of the Meissner effect for tightly bound states and
quasiclassical bound states is revealed.
