ΔE 13.2, fair: the same colour family, but not a straight swap. Orange Brown is more muted, warmer than Rust Orange.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Orange Brown is more muted, warmer than Rust Orange.
The same difference applies the other way round: Rust Orange is more saturated, 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.
See Rust Orange on the colour wheel See Orange Brown on the colour wheel
All matches: Rust Orange equivalents · Orange Brown equivalents