ΔE 10.2, fair: the same colour family, but not a straight swap. Nocturna Shadow is a little lighter, more muted than Stonewall Grey.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Nocturna Shadow is a little lighter, more muted than Stonewall Grey.
The same difference applies the other way round: Stonewall Grey 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 Stonewall Grey on the colour wheel See Nocturna Shadow on the colour wheel
All matches: Stonewall Grey equivalents · Nocturna Shadow equivalents