ΔE 9.6, close: similar, with a visible difference side by side. Medium Sea Grey is a little lighter than Dungeon Stone Grey.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). Medium Sea Grey is a little lighter than Dungeon Stone Grey.
The same difference applies the other way round: Dungeon Stone Grey 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 Dungeon Stone Grey on the colour wheel See Medium Sea Grey on the colour wheel
All matches: Dungeon Stone Grey equivalents · Medium Sea Grey equivalents