ΔE 19.2, loose: different enough that you should pick on purpose. Nurgling Green is noticeably darker, warmer than Light Gray Green.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Nurgling Green is noticeably darker, warmer than Light Gray Green.
The same difference applies the other way round: Light Gray 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 Light Gray Green on the colour wheel See Nurgling Green on the colour wheel
All matches: Light Gray Green equivalents · Nurgling Green equivalents