2D density distribution of spectral slopes S_VIS and S_VNIR in the surface of Ceres, computed from the Dawn/VIR data, provided by Rousseau et al. (2020) and binned in 1° × 1° boxes. Computed slopes (and their errors) for the targeted asteroids belonging to the C complex (green boxes), X complex (blue boxes), and S complex (yellow boxes). The median slope values of the surface of Ceres are represented by a blue cross.