ΔE 15.7, loose: different enough that you should pick on purpose. Straken Green is a little lighter, cooler than Field Green.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Straken Green is a little lighter, cooler than Field Green.
The same difference applies the other way round: Field Green is a little 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 Field Green on the colour wheel See Straken Green on the colour wheel
All matches: Field Green equivalents · Straken Green equivalents