Colour-magnitude diagram showing the colour cut of I_E − H_E ≤ 1.4 used to remove the red elliptical galaxies from our automatically selected dwarf sample. The MER detections in the reference tile are in grey, and the objects in the visual catalogue for score ≥0.8 are in black. The manually cleaned visual dwarfs for score ≥0.8, as described in Fig. 4, are in blue-violet, and the visually identified red elliptical galaxies are in red.