ΔE 10.5, fair: the same colour family, but not a straight swap. Sylvaneth Bark is noticeably darker than Bone Brown.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Sylvaneth Bark is noticeably darker than Bone Brown.
The same difference applies the other way round: Bone Brown is noticeably lighter.
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 Bone Brown on the colour wheel See Sylvaneth Bark on the colour wheel
All matches: Bone Brown equivalents · Sylvaneth Bark equivalents