ΔE 13.1, fair: the same colour family, but not a straight swap. Sun Yellow is much more saturated than Ryza Rust.
Can I use Sun Yellow instead of Ryza Rust?
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Sun Yellow is much more saturated than Ryza Rust.
Can I use Ryza Rust instead of Sun Yellow?
The same difference applies the other way round: Ryza Rust is much 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.