The SMI versus the integrated ultraviolet-optical colors (FUV − V)₀ for Sample A (open stars), Sample B (open triangles, to be considered as lower limits) and Galactic GC (small filled circles). Three remarkable Galactic GCs are highlighted with a concentric open circle, are labelled in boldface and have their CMD presented in an inset box, to show the actual variation of their HB morphology with decreasing (FUV − V)₀ at nearly constant SMI. Two other Galactic clusters and one Sample A cluster, that are mentioned in the text, are also labelled.