ΔE 8.0, close: similar, with a visible difference side by side. Fenrisian Grey is a little darker, cooler than Smoke Grey.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Fenrisian Grey is a little darker, cooler than Smoke Grey.
The same difference applies the other way round: Smoke Grey is a little lighter, warmer.
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 Smoke Grey on the colour wheel See Fenrisian Grey on the colour wheel
All matches: Smoke Grey equivalents · Fenrisian Grey equivalents