ΔE 7.7, close: similar, with a visible difference side by side. USN Light Ghost Grey is more muted than Fenrisian Grey.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). USN Light Ghost Grey is more muted than Fenrisian Grey.
The same difference applies the other way round: Fenrisian 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 Fenrisian Grey on the colour wheel See USN Light Ghost Grey on the colour wheel
All matches: Fenrisian Grey equivalents · USN Light Ghost Grey equivalents