  We investigate the distribution of different classes of spectroscopically
identified sources and theoretical models in the color-color diagrams (CCDs)
combining the near-infrared (NIR) and mid-infrared (MIR) data to develop a
method to classify Outer Galaxy sources detected with the Spitzer Space
Telescope (hereafter Spitzer) SMOG survey in the IRAC 3.6 and 8.0 micrometer
and MIPS 24 micrometer bands. We supplement the Spitzer data with the data from
other satellite and ground-based surveys. The main goal of our study is to
discover and characterize the population of intermediate- and low-mass young
stellar objects (YSOs) in the Outer Galaxy and use it to study star formation
in a significantly different environment than the Galaxy inside the solar
circle. Since the YSOs can be confused with evolved stars in the MIR, these
classes of objects need to be carefully separated. Here we present the initial
results of our analysis using the Ks-[8.0] vs. Ks-[24] CCD as an example. The
evolved stars separated from YSOs in the YSO selection process will be
investigated in detail in the follow-up study.
