ΔE 15.3, loose: different enough that you should pick on purpose. Undead Skintone is a little lighter, cooler than Fur Brown.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Undead Skintone is a little lighter, cooler than Fur Brown.
The same difference applies the other way round: Fur Brown is a little darker, 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 Fur Brown on the colour wheel See Undead Skintone on the colour wheel
All matches: Fur Brown equivalents · Undead Skintone equivalents