ΔE 22.4, loose: different enough that you should pick on purpose. Blueberry is noticeably lighter, warmer than Dark Blue.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 22). Blueberry is noticeably lighter, warmer than Dark Blue.
The same difference applies the other way round: Dark Blue is noticeably darker, 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 Dark Blue on the colour wheel See Blueberry on the colour wheel
All matches: Dark Blue equivalents · Blueberry equivalents