IJN Q1 Anti-Glare Blue-Black vs Dark Leather

How close are they?

ΔE 6.8, close: similar, with a visible difference side by side. Dark Leather is a little lighter than IJN Q1 Anti-Glare Blue-Black.

Can I use Dark Leather instead of IJN Q1 Anti-Glare Blue-Black?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Dark Leather is a little lighter than IJN Q1 Anti-Glare Blue-Black.

Can I use IJN Q1 Anti-Glare Blue-Black instead of Dark Leather?

The same difference applies the other way round: IJN Q1 Anti-Glare Blue-Black 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.