Comparison of metallicity difference versus stellar mass for the gas-phase metallicity as well as for stellar metallicity for the SDSS galaxies. The gas-phase metallicity difference Δ(O/H) with respect to that of MS galaxies is estimated for the combined sample of BPT-SF and BPT-non-SF galaxies identified using the [N II]-BPT and is shown by thinner coloured curves corresponding to ΔSFR_MS varying from −3.2 to 2.2. The thick maroon curve corresponds to the stellar metallicity difference between quiescent galaxies and MS galaxies (Z_⋆(QG) − Z_⋆(MS), while the thick dark green curve corresponds to the stellar metallicity difference between green valley galaxies and MS galaxies (Z_⋆(GVG) − Z_⋆(MS). The stellar metallicity differences are taken from Trussler et al. (2020).