ΔE 10.5, fair: the same colour family, but not a straight swap. Medium Sea Grey is noticeably lighter than N4 Neutral Gray.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Medium Sea Grey is noticeably lighter than N4 Neutral Gray.
The same difference applies the other way round: N4 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 N4 Neutral Gray on the colour wheel See Medium Sea Grey on the colour wheel
All matches: N4 Neutral Gray equivalents · Medium Sea Grey equivalents