Sample standard deviations of the G_BP flux as a function of G_phot for Gaia DR2 stars far from the Galactic Plane (|b|> 30°) for four color ranges G_BP, phot − G_RP, phot. The histogram shows the logarithm of the number of stars per bin on a common scale for all four panels. We note that the total number of stars per panel increases from the top one to the bottom one. The location of the break is marked with a purple line.