HRD of the NSS astrometric solutions without a primary mass estimate. The grey background is the HRD of the full DR3 low-extinction stars (A₀ < 0.05 according to Lallement et al. 2019), equivalent to Fig. 5 of Gaia Collaboration (2018a). The orange points are identified as giants. The red points do not have isochrone match. Violet + do not have an extinction estimate and uncorrected magnitude and colour are therefore used for those. Green points are the white dwarfs with a mass of 0.65 ± 0.16 ℳ_⊙ assumed for Table 3.