Z−J versus V−I colour distribution for our basic sample, with V = F606W, I = F814W, z = F850LP, and J = F125W, as taken from G13. Solid dots are secure redshifts, open triangles are primary redshift solutions, the black square labels ELG30 for which there is no preferred redshift. As in Bayliss et al. (2011), we see a clear separation of redshifts into separate colour groupings, making this diagram useful as a redshift diagnostic for emission-line-selected samples.