Burgundy vs Copper Brown

How close are they?

ΔE 9.7, close: similar, with a visible difference side by side. Copper Brown is a little darker, more muted, warmer than Burgundy.

Can I use Copper Brown instead of Burgundy?

Usually, if you are not matching paint already on the model. Close match (ΔE 10). Copper Brown is a little darker, more muted, warmer than Burgundy.

Can I use Burgundy instead of Copper Brown?

The same difference applies the other way round: Burgundy is a little lighter, more saturated, 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.