ΔE 11.4, fair: the same colour family, but not a straight swap. German Gray is a little lighter, more muted than Nocturne Green.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). German Gray is a little lighter, more muted than Nocturne Green.
The same difference applies the other way round: Nocturne Green is a little darker, 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 Nocturne Green on the colour wheel See German Gray on the colour wheel
All matches: Nocturne Green equivalents · German Gray equivalents