Hexagonally-binned 2D histogram of PAUS W3 galaxies’ i-band k-corrections from redshift z (x-axis) to z = 0 – we assembled these by redshifting each galaxy’s best-fit SED model over the entire z-range, and taking ratios (Eq. (1)) of fluxes to the z = 0 flux. Cells are coloured by the count of galaxies resident in each cell. Solid coloured lines give the running-medians of k₀(z) for five rest-frame colour bins, for which the average colours ⟨u − i⟩ are given in the legend (absolute magnitudes estimated with LEPHARE).