(u − r) colour-stellar mass diagram at z = 0 for each galaxy class. From left to right, the panels correspond to FGs, INs, RINs, BSs, and GRs, respectively. In these panels, different colours correspond to different galaxy number density, ranging from the lowest (lighter colours) to the highest (darker colours) values in each case. In each plot, the shaded region indicates the GV, while the hatched area marks the GZ. The dashed gray vertical line denotes the median log(M_⋆/M_⊙) = 10.07 for our random sample independent of the environment, delimiting the low- and high-mass galaxies. The percentages indicated on the plots represent the fractions of blue (bottom), green (middle), and red (top) galaxies in the low and high stellar mass sub-sample.