ΔE 15.3, loose: different enough that you should pick on purpose. Blueberry is much more saturated, cooler than Coven Purple.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Blueberry is much more saturated, cooler than Coven Purple.
The same difference applies the other way round: Coven Purple is much more muted, 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 Coven Purple on the colour wheel See Blueberry on the colour wheel
All matches: Coven Purple equivalents · Blueberry equivalents