Medium Sea Grey vs IJA Light Grey Green

How close are they?

ΔE 8.6, close: similar, with a visible difference side by side. IJA Light Grey Green is a little lighter, cooler than Medium Sea Grey.

Can I use IJA Light Grey Green instead of Medium Sea Grey?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). IJA Light Grey Green is a little lighter, cooler than Medium Sea Grey.

Can I use Medium Sea Grey instead of IJA Light Grey Green?

The same difference applies the other way round: Medium Sea Grey is a little darker, warmer.

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.