ΔE 7.7, close: similar, with a visible difference side by side. US Olive Drab is a little lighter, more muted than Woodstain Brown.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). US Olive Drab is a little lighter, more muted than Woodstain Brown.
The same difference applies the other way round: Woodstain Brown is a little darker, 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 Woodstain Brown on the colour wheel See US Olive Drab on the colour wheel
All matches: Woodstain Brown equivalents · US Olive Drab equivalents