Spitzer infrared CMDs of the SMC. The wave band corresponding to the ordinate axis is indicated in each panel. The overlaid gray contours indicate densities of sources, and the assumed distance modulus is ﹩\mathrm{DM}\,=18.93﹩. Only sources detected with S/N greater than 10 in the wave bands used in each CMD are plotted. The right side scale on the last panel indicates apparent magnitude.