Comparison between our machine-learning method, LePhare SED fitting, and UVJ colour-colour method, for the selection of quiescent galaxies from the SED Wide mock Euclid catalogue. The following three configurations of input data were used: (i) Euclid photometry only, with no redshift information; (ii) Euclid photometry only, this time with photometric redshifts from Laigle et al. (2016); and (iii) Euclid, ugriz, W1 and W2 photometry, again using photometric redshifts from Laigle et al. (2016).