ΔE 11.2, fair: the same colour family, but not a straight swap. Foul Green is more saturated, warmer than Aquamarine.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Foul Green is more saturated, warmer than Aquamarine.
The same difference applies the other way round: Aquamarine is 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 Aquamarine on the colour wheel See Foul Green on the colour wheel
All matches: Aquamarine equivalents · Foul Green equivalents