[3.4]–[4.6]–[12] μm color-color diagram of WISE thermal sources and blazars. The gray dots represent a sample of 3000 randomly selected mid-IR sources in a region of 0.5 deg radius around the Galactic coordinates (50.411113,−45.668864) and (50.411113, 45.668864). The 66 Swift-XRT-detected sources with available luminosities in the first three WISE bands are marked as black dots. The mid-IR colors of this sample of 66 sources do not agree with the mid-IR colors of stars. Instead, they are more consistent with AGNs, mainly Seyfert galaxies and QSOs. The sources with [4.6]–[12] mag >2 are AGNs and QSOs, while the concentration of sources around 0 [4.6]–[12] mag is mostly made up of normal elliptical galaxies and stars.