ΔE 18.0, loose: different enough that you should pick on purpose. Orange Rust is a little lighter, more saturated, warmer than Sacred Scarlet.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Orange Rust is a little lighter, more saturated, warmer than Sacred Scarlet.
The same difference applies the other way round: Sacred Scarlet is a little darker, more muted, 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 Sacred Scarlet on the colour wheel See Orange Rust on the colour wheel
All matches: Sacred Scarlet equivalents · Orange Rust equivalents