ΔE 8.7, close: similar, with a visible difference side by side. Bright Neutral Grey is more muted than Ulthuan Grey.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Bright Neutral Grey is more muted than Ulthuan Grey.
The same difference applies the other way round: Ulthuan Grey is more saturated.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Ulthuan Grey on the colour wheel See Bright Neutral Grey on the colour wheel
All matches: Ulthuan Grey equivalents · Bright Neutral Grey equivalents