ΔE 19.0, loose: different enough that you should pick on purpose. Dusken Green is much more muted than Emerald Metallic Green.
Can I use Dusken Green instead of Emerald Metallic Green?
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Dusken Green is much more muted than Emerald Metallic Green.
Can I use Emerald Metallic Green instead of Dusken Green?
The same difference applies the other way round: Emerald Metallic Green is much more saturated.
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.