IJN J3 SP (Amber Grey) vs Sand Yellow

How close are they?

ΔE 6.5, close: similar, with a visible difference side by side. Sand Yellow is a little darker, warmer than IJN J3 SP (Amber Grey).

Can I use Sand Yellow instead of IJN J3 SP (Amber Grey)?

Usually, if you are not matching paint already on the model. Close match (ΔE 6). Sand Yellow is a little darker, warmer than IJN J3 SP (Amber Grey).

Can I use IJN J3 SP (Amber Grey) instead of Sand Yellow?

The same difference applies the other way round: IJN J3 SP (Amber Grey) is a little lighter, cooler.

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.