Rust Brown vs Gorgon Brown

How close are they?

ΔE 7.1, close: similar, with a visible difference side by side. Gorgon Brown is a little darker, warmer than Rust Brown.

Can I use Gorgon Brown instead of Rust Brown?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Gorgon Brown is a little darker, warmer than Rust Brown.

Can I use Rust Brown instead of Gorgon Brown?

The same difference applies the other way round: Rust Brown 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.