ΔE 9.2, close: similar, with a visible difference side by side. IJA Light Grey Green is a little darker, more saturated than Medium Sea Gray.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). IJA Light Grey Green is a little darker, more saturated than Medium Sea Gray.
The same difference applies the other way round: Medium Sea Gray is a little lighter, more muted.
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 Gray on the colour wheel See IJA Light Grey Green on the colour wheel
All matches: Medium Sea Gray equivalents · IJA Light Grey Green equivalents