Relative residuals per sample obtained for the predicted epoch observation in CCD7 for a hot (top) and a cold (bottom) G = 13 mag simulated star using BaSeL-3.1 spectral energy distribution library (Lejeune et al. 1997) for BP (left) and RP (right). J and L values refer to parameters in Eq. (14). Pseudo-wavelength values smaller than 15 fall outside the nominal range of the BP instrument (having λ > 680 nm). An approximate correspondence between pseudo-wavelength values and absolute wavelengths can be found in Fig. 4.