Exile Green vs Dark Evergreen

How close are they?

ΔE 20.5, loose: different enough that you should pick on purpose. Dark Evergreen is noticeably darker, more saturated than Exile Green.

Can I use Dark Evergreen instead of Exile Green?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Dark Evergreen is noticeably darker, more saturated than Exile Green.

Can I use Exile Green instead of Dark Evergreen?

The same difference applies the other way round: Exile Green is noticeably lighter, more muted.

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.