ΔE 6.4, close: similar, with a visible difference side by side. Medium Sea Grey is a little darker than Dark Gray 1.
Usually, if you are not matching paint already on the model. Close match (ΔE 6). Medium Sea Grey is a little darker than Dark Gray 1.
The same difference applies the other way round: Dark Gray 1 is a little lighter.
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 Dark Gray 1 on the colour wheel See Medium Sea Grey on the colour wheel
All matches: Dark Gray 1 equivalents · Medium Sea Grey equivalents