Color-magnitude (left panel) and color-color (right panel) plots for sources within a projected distance of 1 Mpc from the COSMOS-FRI 16 (top panel), 31 (center panel), and 70 (bottom panel). Fiducial cluster members and COSMOS-FRI galaxies are distinguished from the remaining sources in the field. Left panel: red-sequence models for galaxies between 10¹⁰ and 5 × 10¹¹ M_⊙ are plotted. Red-sequence Models I and II correspond to a formation redshift z_f = 6.5 and 20, respectively. The horizontal dashed lines show a fiducial ±0.3 dex uncertainty in each model, similarly to Kotyla et al. (2016). Right panel: solid black line distinguishes between fiducial star-forming and quiescent galaxies, respectively. See text for further details.