ΔE 7.8, close: similar, with a visible difference side by side. USN Light Ghost Grey is a little darker than Grey Seer.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). USN Light Ghost Grey is a little darker than Grey Seer.
The same difference applies the other way round: Grey Seer is a little lighter.
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 Grey Seer on the colour wheel See USN Light Ghost Grey on the colour wheel
All matches: Grey Seer equivalents · USN Light Ghost Grey equivalents