  The behaviour of the magnetic field of a neutron star with a superconducting
quark matter core is investigated in the framework of the Ginzburg-Landau
theory. We take into account the simultaneous coupling of the diquark
condensate field to the usual magnetic and to the gluomagnetic gauge fields. We
solve the Ginzburg-Landau equations by properly taking into account the
boundary conditions, in particular, the gluon confinment condition. We found
the distribution of the magnetic field in both the quark and hadronic phases of
the neutron star and show that the magnetic field penetrates into the quark
core in the form of quark vortices due to the presence of Meissner currents.
