ΔE 17.7, loose: different enough that you should pick on purpose. Pickle Green is noticeably darker, more saturated than Feral Green.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Pickle Green is noticeably darker, more saturated than Feral Green.
The same difference applies the other way round: Feral Green is noticeably lighter, 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 Feral Green on the colour wheel See Pickle Green on the colour wheel
All matches: Feral Green equivalents · Pickle Green equivalents