CAMD for the cluster members (gray) and RRL (purple dots with error bars). Possible primary RRL stars are shown as coloured circles, and the corresponding secondary companions as triangles. The two tracks shown for primaries correspond to the G19 (large circles) and L22 extinctions (small circles). The colour scale represents the mass of the companion star. The IS limits for RRab from Marconi et al. (2015) and expected HB luminosity for the cluster’s metallicity from the Garofalo et al. (2022) PLZ relation (as in Fig. 2) are shown by the dotted lines, the shaded areas correspond to their respective uncertainties.