ΔE 15.8, loose: different enough that you should pick on purpose. Transparent Orange is noticeably darker, more muted, warmer than Ryza Rust. They are different kinds of paint: Citadel Ryza Rust is an opaque base/layer paint and Pro Acryl Transparent Orange is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Transparent Orange is noticeably darker, more muted, warmer than Ryza Rust. They are different kinds of paint.
The same difference applies the other way round: Ryza Rust is noticeably 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 Ryza Rust on the colour wheel See Transparent Orange on the colour wheel
All matches: Ryza Rust equivalents · Transparent Orange equivalents