ΔE 6.8, close: similar, with a visible difference side by side. Green Brown is a little lighter, warmer than Poison Green.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Green Brown is a little lighter, warmer than Poison Green.
The same difference applies the other way round: Poison Green is a little darker, 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 Poison Green on the colour wheel See Green Brown on the colour wheel
All matches: Poison Green equivalents · Green Brown equivalents