ΔE 18.6, loose: different enough that you should pick on purpose. Elf Skin Tone is noticeably lighter, more saturated, warmer than Rust in Peace.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Elf Skin Tone is noticeably lighter, more saturated, warmer than Rust in Peace.
The same difference applies the other way round: Rust in Peace is noticeably 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 Rust in Peace on the colour wheel See Elf Skin Tone on the colour wheel
All matches: Rust in Peace equivalents · Elf Skin Tone equivalents