Radio luminosity densities and infrared colors for the radio sources in our sample. Top. 1.4 GHz Radio luminosity density as a function of redshift. Sources are distinguished between AGN (black circles), starbursts (orange triangles), intermediate disks (green squares), and spheroids according to the color-based classification by Stern et al. (2012) and Jarrett et al. (2017). The horizontal line is at L_ν = 2 × 10³² erg s⁻¹ Hz⁻¹ and separates low-luminosity radio sources from high-luminosity radio sources. Bottom. WISE color-color plot. Color coding of the data-points is the same as in the top panel. Black dashed lines are overplotted to distinguish the different types of objects (AGN, ULIRGs, spheroids, intermediate disks, starbusts, and LIRGs).