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