ΔE 12.8, fair: the same colour family, but not a straight swap. Stonewall Grey is noticeably lighter than N6 Neutral Gray.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Stonewall Grey is noticeably lighter than N6 Neutral Gray.
The same difference applies the other way round: N6 Neutral Gray is noticeably 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 N6 Neutral Gray on the colour wheel See Stonewall Grey on the colour wheel
All matches: N6 Neutral Gray equivalents · Stonewall Grey equivalents