ΔE 13.5, fair: the same colour family, but not a straight swap. Purple Black is a little lighter than Dryad Bark.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Purple Black is a little lighter than Dryad Bark.
The same difference applies the other way round: Dryad Bark is a little darker.
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 Dryad Bark on the colour wheel See Purple Black on the colour wheel
All matches: Dryad Bark equivalents · Purple Black equivalents