ΔE 7.3, close: similar, with a visible difference side by side. Feral Green is a little lighter, more saturated than Weed Green.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Feral Green is a little lighter, more saturated than Weed Green.
The same difference applies the other way round: Weed Green is a little darker, more muted.
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 Weed Green on the colour wheel See Feral Green on the colour wheel
All matches: Weed Green equivalents · Feral Green equivalents