Color–magnitude relation for objects detected in the PLCK G287.0+32.9 field from Subaru photometry. All magnitudes have been extinction-corrected. The red sequence is selected using the 4000 Å break, which is bracketed by the g- and r-band filters at z = 0.385. Cluster members confirmed by KECK/DEIMOS spectroscopy are highlighted red and form a red sequence at ﹩g-r\sim 1.5﹩. Galaxies that are included in the weak-lensing source catalog (blue) are chosen to span a region fainter and bluer than the red sequence. Spectroscopically confirmed cluster members are removed from the source catalog.