  We investigate the prospects to observe a high energy neutrino signal from
dark matter annihilations in the Sun in scenarios where the dark matter is a
Majorana fermion that couples to a quark and a colored scalar via a Yukawa
coupling. In this minimal scenario, the dark matter capture and annihilation in
the Sun can be studied in a single framework. We find that, for small and
moderate mass splitting between the dark matter and the colored scalar, the
two-to-three annihilation $q \bar q g$ plays a central role in the calculation
of the number of captured dark matter particles. On the other hand, the
two-to-three annihilation into $q \bar q Z$ gives, despite its small branching
fraction, the largest contribution to the neutrino flux at the Earth at the
highest energies. We calculate the limits on the model parameters using IceCube
observations of the Sun and we discuss their interplay with the requirement of
equilibrium of captures and annihilations in the Sun and with the requirement
of thermal dark matter production. We also compare the limits from IceCube to
the limits from direct detection, antiproton measurements and collider
searches.
