(a) Replication of Fig. 7 from Morate et al. (2019), but using primitive asteroids among the Gaia DR3 dataset. Colors indicate objects classified with Tholen taxonomy. Red lines are the 2σ dispersion of the sample as in Morate et al. (2019), corresponding to their Eq. (5). (b) Same as (a) but with main belt asteroids (in grey) separated from Cybeles (in green), Hildas (in blue), and Trojans (in red). See the main text for the semi-major axis values used to separate these populations, (c), (d), (e), and (ſ) show the visible spectral slope distribution for the four dynamical populations observed for absolute magnitudes 8 < H < 12 (in blue) and 12 < H < 16 (in beige).