Colour-colour diagrams showing uiK_s (upper panel) and gri (lower panel) for the detected sources in ERO-F data (grey points), using the photometry of the Fornax Deep Survey (FDS, Peletier et al. 2020) provided in Saifollahi et al. (2021a). GCs (red points) are known to show a well-defined sequence in uiK_s separated from stars, except those at the bluest end (light blue points), and from galaxies (dark blue points). More than 90% of the bright GC candidates with I_E < 21.5 (green points) selected in this work are located on this diagram, while less than 10% are consistent with being a foreground star or background galaxy.