ΔE 15.1, loose: different enough that you should pick on purpose. Sap Green Hue is noticeably darker, more saturated, warmer than Straken Green.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Sap Green Hue is noticeably darker, more saturated, warmer than Straken Green.
The same difference applies the other way round: Straken Green is noticeably lighter, more muted, 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 Straken Green on the colour wheel See Sap Green Hue on the colour wheel
All matches: Straken Green equivalents · Sap Green Hue equivalents