Possible manifestation of heavy stable colored particles in cosmology and cosmic rays

We discuss the cosmological implications as well as possible observability of massive stable colored particles which often appear in the discussion of physics beyond the standard model. We show that if their masses are bigger than a few hundred GeV and they saturate the halo density and/or they occur with closure density of the universe, they can be ruled out by existing limits on heavy stable particles from analysis of anomalously heavy isotopes of ordinary nuclei as well as from the observations in WIMP detectors. We also derive constraints on their masses if they annihilate to produce gamma rays. We then comment on the possibility that these particles could be responsible for the ultrahigh energy (UHE) cosmic rays with energies $>~{10}^{20}\mathrm{eV}$ observed in several recent experiments and in particular point out that their low inelasticity argues against the possibility they can explain the observed UHE events.