ΔE 17.4, loose: different enough that you should pick on purpose. Demonic Skin is more muted, warmer than Garnet Purple.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Demonic Skin is more muted, warmer than Garnet Purple.
The same difference applies the other way round: Garnet Purple is 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 Garnet Purple on the colour wheel See Demonic Skin on the colour wheel
All matches: Garnet Purple equivalents · Demonic Skin equivalents