Distributions in colour (left) and redshift (right) of our locally brightest galaxies and of the SDSS/DR7 population from which they were drawn. Black histograms refer to the parent sample and red histograms to the locally brightest galaxies. The panels in each set correspond to five disjoint ranges of log ₁₀M_∗/M_⊙, as indicated in the labels. In the left-hand set, additional labels give the number of galaxies contributing to the parent (black) and locally brightest (red) histograms. Dashed vertical lines in these same panels indicate the colour we use to separate red and blue galaxies in Fig. 3 below.