Color–color diagram to identify recently quenched elliptical (RQE) galaxies. The colors are in AB magnitudes and K-corrected at z = 0. The symbols for the galaxies are the same as Fig. 2. The thick black lines enclose the non-star-forming region of McIntosh et al. (2014) based on Holden et al. (2012). The RQE selection region is empirically defined as the green shaded triangle by McIntosh et al. (2014). Nine isolated elliptical galaxies are inside this region and are shown in magenta open squares.