ΔE 11.5, fair: the same colour family, but not a straight swap. Coven Purple is a little darker, more saturated, warmer than Mauve.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Coven Purple is a little darker, more saturated, warmer than Mauve.
The same difference applies the other way round: Mauve is a little lighter, more muted, cooler.
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 Mauve on the colour wheel See Coven Purple on the colour wheel
All matches: Mauve equivalents · Coven Purple equivalents