ΔE 15.1, loose: different enough that you should pick on purpose. Ghoul Skin is noticeably darker, more saturated, cooler than Rakarth Flesh.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Ghoul Skin is noticeably darker, more saturated, cooler than Rakarth Flesh.
The same difference applies the other way round: Rakarth Flesh 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 Rakarth Flesh on the colour wheel See Ghoul Skin on the colour wheel
All matches: Rakarth Flesh equivalents · Ghoul Skin equivalents