ΔE 13.0, fair: the same colour family, but not a straight swap. Purple is a little lighter, cooler than Dark Plum.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Purple is a little lighter, cooler than Dark Plum.
The same difference applies the other way round: Dark Plum 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 Dark Plum on the colour wheel See Purple on the colour wheel
All matches: Dark Plum equivalents · Purple equivalents