F200W-F444W as a function of the rest frame equivalent width of the PAH, for cluster (stars) and field (circle) galaxies. Galaxies are color coded by their Δ(F200W-F444W), which is measured as the difference between their measured color and the color they should have if they were on the red sequence, given their F200W magnitude. The squared symbol indicates 23903, the only galaxy most likely hosting an AGN.