ΔE 7.5, close: similar, with a visible difference side by side. Ink Yellow is more saturated than Ryza Rust. They are different kinds of paint: Citadel Ryza Rust is an opaque base/layer paint and Vallejo Ink Yellow is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Ink Yellow is more saturated than Ryza Rust. They are different kinds of paint.
The same difference applies the other way round: Ryza Rust is more muted.
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 Ink Yellow on the colour wheel
All matches: Ryza Rust equivalents · Ink Yellow equivalents