Rust vs Swamp Brown

How close are they?

ΔE 6.1, close: similar, with a visible difference side by side. Swamp Brown is a little lighter than Rust. They are different kinds of paint: Army Painter Rust is an opaque base/layer paint and Green Stuff World Swamp Brown is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.

Can I use Swamp Brown instead of Rust?

Usually, if you are not matching paint already on the model. Close match (ΔE 6). Swamp Brown is a little lighter than Rust. They are different kinds of paint.

Can I use Rust instead of Swamp Brown?

The same difference applies the other way round: Rust 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.