ΔE 17.9, loose: different enough that you should pick on purpose. Armor Green is a little darker, much more muted, cooler than Dark Green.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Armor Green is a little darker, much more muted, cooler than Dark Green.
The same difference applies the other way round: Dark Green is a little lighter, much more saturated, 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 Dark Green on the colour wheel See Armor Green on the colour wheel
All matches: Dark Green equivalents · Armor Green equivalents