Euclid CMDs. The grey dots show all sources in the master catalogue for each galaxy, while the open and filled blue circles are our new candidates classified as ‘possible’ or ‘likely’, respectively. For NGC 2403, the previously known GCs are shown in red. Formal uncertainties on the photometry are generally less than 0.01 mag, but see Sect. 4.3 for a detailed discussion of the uncertainties.