ΔE 24.9, loose: different enough that you should pick on purpose. Blueberry is noticeably lighter, more muted, warmer than Imperium Blue.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 25). Blueberry is noticeably lighter, more muted, warmer than Imperium Blue.
The same difference applies the other way round: Imperium Blue is noticeably darker, more saturated, 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 Imperium Blue on the colour wheel See Blueberry on the colour wheel
All matches: Imperium Blue equivalents · Blueberry equivalents