  We investigate the color-singlet order parameters and the quark description
of the Nambu-Goldstone (NG) bosons in the color-flavor locked (CFL) phase. We
put emphasis on the NG boson (phason) called ``H'' associated with the
$\mathrm{U_B(1)}$ symmetry breaking. We qualitatively argue the nature of H as
the second sound in the hydrodynamic regime. We articulate, based on a diquark
picture, how the structural change of the condensates and the associated NG
bosons occurs continuously from hadronic to CFL quark matter if the
quark-hadron continuity is realized. We sharpen the qualitative difference
between the flavor octet pions and the singlet phason. We propose a conjecture
that superfluid H matter undergoes a crossover to a superconductor with
tightly-bound diquarks, and then a crossover to superconducting matter with
diquarks dissociated.
