ΔE 19.4, loose: different enough that you should pick on purpose. Succubus Skin is noticeably darker, warmer than Old Red.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Succubus Skin is noticeably darker, warmer than Old Red.
The same difference applies the other way round: Old Red is noticeably lighter, 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 Old Red on the colour wheel See Succubus Skin on the colour wheel
All matches: Old Red equivalents · Succubus Skin equivalents