ΔE 8.8, close: similar, with a visible difference side by side. Pastel Green is more muted than Olive Green.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Pastel Green is more muted than Olive Green.
The same difference applies the other way round: Olive Green 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 Olive Green on the colour wheel See Pastel Green on the colour wheel
All matches: Olive Green equivalents · Pastel Green equivalents