Rest-frame U − V versus V − J colours for galaxies with stellar masses exceeding 10¹⁰ M_⊙ to differentiate between quiescent and star-forming galaxies. The arrow indicates the reddening vector for dust. Combining both colours facilitates a distinction between both galaxy types, even when there is significant reddening by dust. In grey is the distribution of galaxies from GCLASS that are between 0.85 < z < 1.20, but outside the clusters. A relative density scale is provided. The red points show photo-z selected cluster members with projected position less than 2 arcmin from the cluster centres.