Normalized distribution with g − r galaxy color. We compare the distribution of sources in our sample, separated by ionization source (purple for SF vs. pink for AGNs) and galaxy cluster type (filled histogram for mergers vs. hatched histograms for relaxed clusters). Samples are matched in magnitude, luminosity, and cluster-centric distance. AGN hosts have redder colors, while star-forming galaxies are on average bluer, especially in merging clusters.