ΔE 8.9, close: similar, with a visible difference side by side. Red is a little darker, more saturated than Rust Brown.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Red is a little darker, more saturated than Rust Brown.
The same difference applies the other way round: Rust Brown is a little lighter, more muted.
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.
See Rust Brown on the colour wheel See Red on the colour wheel
All matches: Rust Brown equivalents · Red equivalents