ΔE 17.3, loose: different enough that you should pick on purpose. Grunge Brown is noticeably darker, more saturated than Caucasian Skin.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Grunge Brown is noticeably darker, more saturated than Caucasian Skin.
The same difference applies the other way round: Caucasian Skin is noticeably lighter, more muted.
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 Caucasian Skin on the colour wheel See Grunge Brown on the colour wheel
All matches: Caucasian Skin equivalents · Grunge Brown equivalents