ΔE 53.2, loose: different enough that you should pick on purpose. Rust is noticeably darker, much more muted, warmer than Fluor Rose.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 53). Rust is noticeably darker, much more muted, warmer than Fluor Rose.
The same difference applies the other way round: Fluor Rose is noticeably lighter, much 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 Fluor Rose on the colour wheel See Rust on the colour wheel
All matches: Fluor Rose equivalents · Rust equivalents