Rest-frame (M_NUV − M_r) vs. (M_r − M_J) colour–colour diagram for AGN host galaxies selected according to the KEx (left panel) and the MEx (right panel) line diagnostic methods. Dashed lines mark regions that separate quiescent (upper left corner) and star-forming galaxies. The symbols are the same as in Fig. 7. The zCOSMOS non-AGN sample, a comparison sample of galaxies with a similar mass distribution at 0.3 ≤ z_sp ≤ 0.9, is represented by grey points. Colour distributions are included in the upper and right panels. The comparison sample is represented by dotted grey circles.