ΔE 20.5, loose: different enough that you should pick on purpose. Foul Green is noticeably lighter, cooler than Sybarite Green.
✓ Herrick Games paint comparison chart lists these two as equivalents.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Foul Green is noticeably lighter, cooler than Sybarite Green.
The same difference applies the other way round: Sybarite Green is noticeably darker, warmer.
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 Sybarite Green on the colour wheel See Foul Green on the colour wheel
All matches: Sybarite Green equivalents · Foul Green equivalents