ΔE 9.6, close: similar, with a visible difference side by side. Orange Rust is a little lighter, more saturated than Deep Brown.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). Orange Rust is a little lighter, more saturated than Deep Brown.
The same difference applies the other way round: Deep Brown is a little darker, 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 Deep Brown on the colour wheel See Orange Rust on the colour wheel
All matches: Deep Brown equivalents · Orange Rust equivalents