I here present results from analysis of recently released All Sky WISE survey on cosmological evolution of blazars. Starting from the latest version of ROMA-BZCAT catalog I retrieved WISE observations of all known blazars and investigate the spectral evolution of all sources with known redshift in order to compare their behavior with those detected by Fermi. For BL Lac sources I found an evolutionary trend of their average IR colors leading them on WISE color-color diagrams, as their redshift increases, from the region occupied by high frequency peaked source to the region where low frequency peaked BL Lacs overlap with FSRQs; the latter, on the other hand, follow on the same diagrams a path that leads them, as their redshift increases, from the region where they overlap with low frequency peaked BL Lacs to eventually fall outside the region defined by Fermi-detected blazars.

These evolutionary trends are also shown by blazar IR spectral indices that clearly indicates a transition across the WISE bands of different spectral components of the blazar IR emission, such as host galaxy, disk emission and jet. In fact, when considering the intrinsic (i.e. blue-shifted to the emitting frame) spectral energy distributions for all WISE blazars with known redshift, these show an increasing evidence of ongoing accretion with increasing redshift, indicating that the observed IR WISE colors of blazars are likely due to cosmological evolutionary effects linked to the interactions of blazar host galaxies with group companions.