(g − r) colour-magnitude diagrams of the CIRS (left) and HeCS (right) galaxies, including k-corrections. The galaxies have a cluster-centric distance smaller than 3R₂₀₀ and line-of-sight velocity |v_los − v_cl|< 3000 km s⁻¹. The black solid curve in the right panel shows the fit by Rines et al. (2013) derived from the HeCS galaxies. The black dashed, dotted, and dash-dotted lines show the ±0.30, ±0.40, ±0.50 shifts of the same fit. In the left panel, the black solid line shows the Rines et al.’s fit with an offset of −0.03 mag. The black dashed, dotted, and dash-dotted lines show the ±0.30, ±0.40, ±0.50 mag shifts of this line.