CMDs in apparent G magnitude vs. (G_BP − G_RP) colour defined by RR Lyrae stars in the DR3 clean catalogue. Left panel: G and G_BP−G_RP CMD of RR Lyrae stars in the DR3 clean catalogue that lie in GCs (red points) and dSph galaxies (blue points), for which colour information is available (2558 out of 2790 sources). Each concentration of points corresponds to a different system. Middle panel: G and G_BP−G_RP CMD of the whole sample of RR Lyrae stars for which colour information is available, 215 116 sources (out of 270 905). Different colours show the variable stars in the LMC (26 468 sources; cyan symbols), SMC (4353 sources; yellow symbols), and all-sky (184 280 sources; grey symbols) regions as defined in Sect. 2. Right panel: lower panel same as in the middle panel, but blue, green, and red points mark RR Lyrae stars with σ_ϖ/ϖ < 0.5 (58 018 sources), < 0.2 (13 377 sources), and < 0.1 (4670 sources), respectively.