Three-color composite HST image of ESO 338-4. Red is centered on the Hα emission line with the F656N filter, blue is in UV with the F140LP filter, and green is the F550M filter. The ULX point source positions (Table 1) along their 1σ uncertainties are overlaid on this image in black. We highlight the boundaries of the Chandra count distribution of each source at a 3σ level through white ellipses (Fig. 1). An association between ULX2 and CL85, and ULX3 and CL82 is established as their positional uncertainty is within the optical extent of the clusters.