ΔE 10.6, fair: the same colour family, but not a straight swap. Gray Green (Luftwaffe) is a little lighter than Night Sky.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Gray Green (Luftwaffe) is a little lighter than Night Sky.
The same difference applies the other way round: Night Sky is a little darker.
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 Night Sky on the colour wheel See Gray Green (Luftwaffe) on the colour wheel
All matches: Night Sky equivalents · Gray Green (Luftwaffe) equivalents