ΔE 15.6, loose: different enough that you should pick on purpose. Light Brown is a little darker, more muted, warmer than Rust Orange.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Light Brown is a little darker, more muted, warmer than Rust Orange.
The same difference applies the other way round: Rust Orange is a little lighter, 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 Light Brown on the colour wheel
All matches: Rust Orange equivalents · Light Brown equivalents