  We study the spectrum of light plasmons in the (gapped and gapless)
two-flavor color superconducting phases and its connection with the
chromomagnetic instabilities and the structure of the ground state. It is
revealed that the chromomagnetic instabilities in the 4-7th and 8th gluonic
channels correspond to two very different plasmon spectra. These spectra lead
us to the unequivocal conclusion about the existence of gluonic condensates
(some of which can be spatially inhomogeneous) in the ground state. We also
argue that spatially inhomogeneous gluonic condensates should exist in the
three-flavor quark matter with the values of the mass of strange quark
corresponding to the gapless color-flavor locked state.
