Color–color diagrams used for YSO identification in phase 2 (panel a) and phase 3 (panels b and c) classification schemes suggested by Gutermuth et al. (2009) for an example of GMF 39 (CFG047.06+0.26). The Class I sources identified in phase 2 and the protostars identified in phase 3 are marked with red dots. The Class II sources isolated in phase 2 are labeled with green dots while the transition disks classified in phase 3 are shown with blue dots.