ΔE 15.0, loose: different enough that you should pick on purpose. Mortarion Green Clear is a little darker, much more muted than Emerald Forest.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Mortarion Green Clear is a little darker, much more muted than Emerald Forest.
The same difference applies the other way round: Emerald Forest is a little lighter, 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.
See Emerald Forest on the colour wheel See Mortarion Green Clear on the colour wheel
All matches: Emerald Forest equivalents · Mortarion Green Clear equivalents