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