Color–magnitude diagrams of GCNS targets. The upper two panels show all GCNS targets with G, G _BP, and G _RP measurements. Red ellipses indicate the locations of evolved stars and white dwarfs in both plots, the red hook in the G _BP − G _RP plot, and a region of high BP/RP flux excess in the G − G _RP plot. The lower two panels show only the main-sequence stars used in this study.