2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/163340R-mode instabilities lead to specific signatures in the evolution of rotating pulsars, and may provide a unique signature which can identify the phase of matter that exists in the interiors of such objects. The contributions of quarks' bulk and shear viscosities to the dissipation of r-mode instabilities are studied. It is shown that (contrary to earlier works) the quark contribution is \emph{not} fully suppressed in the presence of fully gapped color-superconducting phase due to the fact that the bulk viscosity is a resonance effect between the density oscillation on one side, and the interaction rates that try to restore $β$-equilibrium during these oscillations on the other. This will have an effect on the structure of the r-mode instability window and will affect the angular momentum evolution of pulsars.11 pages, 6 figuresAstrophysicstext