Total dispersion histograms used to calculate the instrumental dispersion as a function of magnitude and color. Each page shows the 15 plots for a given G magnitude range, starting with 3.0–5.3 mag. The three columns show the histograms for G (left), G_BP (center) and G_RP (right). The five rows show the G_BP – G_RP ranges, from top to bottom: −1.0–0.2, 0.2–1.0, 1.0–1.5, 1.5–2.5, and 2.5–8.0 (in mag). The histograms have a uniform bin size in logarithmic units (see the text for the bins used for fitting) and both the horizontal and vertical scales are logarithmic and the same in all plots to allow for better comparisons. The dotted diagonal line indicates the location of one star per bin to estimate Poisson fluctuations.