Central overdensities (COD) versus brightness for the red, IR-only, blue and all subsamples. Each row plots the COD around the labeled 3C source, which are sorted by redshift. The rows are subsequently shifted vertically by 20 arcmin⁻². The total COD integrated over the brightness range is labeled as Σ. The 3C sources themselves have been excluded from the counts. The brightness bins have a width of 1 mag, which results in small numbers of objects per bin. A COD of N = 5 per square arcmin translates to 1 galaxy per cell of r = 15″.