ΔE 16.6, loose: different enough that you should pick on purpose. Faded Green is noticeably darker, warmer than Mossy Green.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Faded Green is noticeably darker, warmer than Mossy Green.
The same difference applies the other way round: Mossy Green is noticeably lighter, 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 Mossy Green on the colour wheel See Faded Green on the colour wheel
All matches: Mossy Green equivalents · Faded Green equivalents