Colour–colour diagram, [3.6]−[4.5] versus [5.8]−[8.0], for all Spitzer-GLIMPSE sources with measurements in the four bands, and situated at less than 7′ from the exciting star of G319.88+00.79. The big red dots correspond to sources with measurements more accurate than 0.2 mag in all four bands; the small red dots are for the less accurate sources. The blue dots are for candidate xAGB stars, following Robitaille et al. (2008). The location of YSOs dominated by a disk (Class II YSOs) and by an envelope (Class I YSOs) are indicated, following Allen et al. (2004; see also Megeath et al. 2004). The extinction law is that of Indebetouw et al. (2005). The sources discussed in the text, mainly candidate Class I YSOs, are identified.