IRAC colors of the detected X-ray sources, based on the colors presented in Table 7. The green circles correspond to the X-ray sources located outside of the visual extent of NGC 45, the red stars correspond to the X-ray sources located within the visual extent of NGC 45 and the blue stars correspond to the radio sources detected by our radio observations that were also detected by IRAC. The dashed line indicates the location of the “Lacy wedge” (Lacy et al. 2005) that broadly defines the colors of galaxies, consistent with the interpretation that these sources are background galaxies seen in projection toward NGC 45. See Sections 3.5 and 7.