P−G-band amplitude distribution of 19 923 candidate Cepheids and RR Lyrae stars (grey filled cicles) identified by the Classification pipeline of the general variability processing in the C0 photometry of the Gaia SEP. Units are in days and magnitude on the X- and Y-axis, respectively. The bottom panel is an expansion of the top panel for the region of P ≤ 1 d. Orange and cyan filled circles mark F and 1O Cepheids; red, blue, and green open circles are RRab, RRc, and RRd pulsators known from the OGLE-III and OGLE-IV GSEP catalogues. Amplitudes are values computed by running the SOS Cep&RRL pipeline on C0 photometry. The strong peak around P = 0.25 d is an alias due to the rotation period of Gaia around its axis.