ΔE 13.4, fair: the same colour family, but not a straight swap. Ryza Rust is more muted, warmer than Ochre.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Ryza Rust is more muted, warmer than Ochre.
The same difference applies the other way round: Ochre 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 Ochre on the colour wheel See Ryza Rust on the colour wheel
All matches: Ochre equivalents · Ryza Rust equivalents