Normalised metallicity distribution of 64 957 RR Lyrae stars in the sample of 140 784 confirmed sources for which a photometric [Fe/H] value was inferred from the ϕ₃₁ Fourier parameter of the G-band light curve. The sources were divided according to the three separate regions (All-Sky, LMC, and SMC) defined in Sect. 2. Green, pink, and blue histograms represent All-Sky, LMC, and SMCvariables, respectively. The three distributions peak at mean values of [Fe/H] approximately − 1.15 ± 0.6, − 1.3 ± 0.7, and − 1.6 ± 0.7 dex for the MW, LMC, and SMC RR Lyrae stars, respectively.