ΔE 28.9, loose: different enough that you should pick on purpose. Orc Skin is noticeably darker, more saturated, cooler than Zombie Skin.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 29). Orc Skin is noticeably darker, more saturated, cooler than Zombie Skin.
The same difference applies the other way round: Zombie Skin is noticeably lighter, more muted, warmer.
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 Zombie Skin on the colour wheel See Orc Skin on the colour wheel
All matches: Zombie Skin equivalents · Orc Skin equivalents