SEDs of the BCG. We have grouped them by 5.5/8.0 μm color. The fluxes are normalized to the 3.6 μm flux. (a) These objects are among the reddest objects with ﹩F_{8\mu \mathrm{m}\,}/ F_{5.8\mu \mathrm{m}\,}> 1.3﹩. They also have unresolved red nuclei seen in the IRAC color maps. These three have high [O III]/Hβ ratios suggesting that they host an AGN. Abell 2146 has a blue 24–70 μm flux ratio suggesting that the dust is warmer than the others. (b) Additional galaxies with ﹩F_{8\mu \mathrm{m}\,}/ F_{5.8\mu \mathrm{m}\,}> 1.3﹩. These galaxies have strong mid‐infrared excesses compared to a quiescent elliptical galaxy and all were detected at 70 μm. (c) BCGs with ﹩1.0< F_{8\mu \mathrm{m}\,}/ F_{5.8\mu \mathrm{m}\,}< 1.3﹩. (d, e) BCGs with ﹩0.75< F_{8\mu \mathrm{m}\,}/ F_{5.8\mu \mathrm{m}\,}< 1.0﹩. (f, g) BCGs with ﹩F_{8\mu \mathrm{m}\,}/ F_{5.8\mu \mathrm{m}\,}< 0.75﹩. Most of these are consistent with a quiescent stellar population. Objects that are not detected at 70 μm have upper limits on this plot at 70 μm ~3–10 times the flux at 3.6 μm. (h) Additional BCGs with ﹩F_{8\mu \mathrm{m}\,}/ F_{5.8\mu \mathrm{m}\,}< 0.75﹩ and that are detected at 70 μm.