Color–color diagrams using the AllWISE catalog. Left: W1W2 vs. W2W3 diagram with SVM selected YSO Class I (red squares) and Class II (green triangles) candidates. Pink diamonds mark the position of SVM-selected YSO candidates with measured distances for Class II. Blue × and orange + symbols show the position of the training YSO I (151 objects) and II (346 objects), respectively, based on the Spitzer selection in the entire SMOG survey area. Black lines mark the boundaries of color spaces within which Class I and Class II are expected to lie following the work of Fischer et al. (2016). Right: W1W2 vs. W2W3 diagram showing the positions of spectroscopically confirmed YSOs and AGB stars from Jones et al. (2017). Green triangles mark all YSOs, yellow diamonds mark the carbon-rich post AGB stars (PC-AGB), blue crosses signs mark the carbon-rich AGB stars (C-AGB), magenta × symbols mark oxygen-rich post AGB stars (PO-AGB), and pink × symbols mark the oxygen-rich AGB stars (O-AGB).