ΔE 9.1, close: similar, with a visible difference side by side. Sombre Grey is a little darker, warmer than Celestra Grey.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Sombre Grey is a little darker, warmer than Celestra Grey.
The same difference applies the other way round: Celestra Grey is a little lighter, cooler.
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 Celestra Grey on the colour wheel See Sombre Grey on the colour wheel
All matches: Celestra Grey equivalents · Sombre Grey equivalents