ΔE 11.1, fair: the same colour family, but not a straight swap. Orange Brown is a little lighter, more muted than Fresh Rust.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Orange Brown is a little lighter, more muted than Fresh Rust.
The same difference applies the other way round: Fresh 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 Fresh Rust on the colour wheel See Orange Brown on the colour wheel
All matches: Fresh Rust equivalents · Orange Brown equivalents