ΔE 8.3, close: similar, with a visible difference side by side. Green Grey is warmer than Medium Seagray BS381C/637.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Green Grey is warmer than Medium Seagray BS381C/637.
The same difference applies the other way round: Medium Seagray BS381C/637 is 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 Medium Seagray BS381C/637 on the colour wheel See Green Grey on the colour wheel
All matches: Medium Seagray BS381C/637 equivalents · Green Grey equivalents