Optical CMDs of NGC 6752 and ω Cen. The stars included in the spectroscopic samples are identified with large red dots. NGC 6752: also shown are the variable stars V16 and V17 (stars) and the four bright blue stragglers (triangles). The magnitudes are from the HUGS survey (Nardiello et al. 2018). ω Cen: the blue-hook stars in ω Cen are marked with blue squares. The magnitudes for the central fields of view (1 to 6 in Table 1) are from the catalog of Bellini et al. (2017a) and the magnitudes for stars in the outer fields (7, 8, 11, and 12) are from Anderson & van der Marel (2010).