Estimate of the colour sampling rate (CSR) of VIPERS The plot shows the fraction of galaxies that are selected by the VIPERS colour-colour criteria as a function of redshift, when applied to a sample of galaxies from the VVDS-Deep and VVDS-Wide surveys (Le Fèvre et al. 2013a). This is a highly significant test, given that the original colour-colour boundaries to select VIPERS targets were calibrated on the same VVDS data. Both W1 and W4 fields provide consistent selection functions, yielding a colour selection function that is essentially unity above z = 0.6 and can be consistently modelled in the transition region 0.4 <z< 0.6.