Deep Purple vs Blueberry

How close are they?

ΔE 21.2, loose: different enough that you should pick on purpose. Blueberry is noticeably lighter, more saturated, cooler than Deep Purple.

Can I use Blueberry instead of Deep Purple?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Blueberry is noticeably lighter, more saturated, cooler than Deep Purple.

Can I use Deep Purple instead of Blueberry?

The same difference applies the other way round: Deep Purple is noticeably darker, 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.