Projections on the three WISE color-color planes of spectroscopically identified sources discussed in this paper with counterparts in WIBRaLS. Red, blue, and yellow points respectively indicate candidates classified as BZQ, BZB, and BZG sources based on their optical spectra. Circles and stars are associated with sources observed in this campaign and sources for which spectra are available in the literature, respectively. The black lines on the three planes are the isodensity contours of the 2D projections of the 3D color distribution of locus sources (not plotted for clarity) used to define the WIBRaLS 3D model in the WISE colors space.