The contribution of thermally excited electron-positron pairs to the bulk properties of the color-flavor locked quark phase inside compact stars is examined .
The presence of these pairs causes the photon mean free path to be much smaller than a typical core radius ( R _ { 0 } \simeq 1 km ) for all temperatures above 25 keV so that the photon contribution to the thermal conductivity is much smaller than that of the Nambu-Goldstone bosons .
We also find that the electrons and positrons dominate the electrical conductivity , while their contributions to the total thermal energy is negligible .