CMDs in y₀, c_y,0 for the nine GCs, seven in common with our spectroscopic survey. Blue symbols indicate P stars and red symbols IE stars, all confirmed members on the basis of their RVs. For NGC 6205 (=M 13) and NGC 6341 (=M 92), whose spectroscopic data are not homogeneous with the seven other GCs, we use light blue and magenta, respectively. For NGC 6397 we display in an inset the results from Lind et al. (2009, 2011), shown on our same scale in magnitude, and on an expanded scale in c_y,0.