Character Blue vs Blueberry

How close are they?

ΔE 18.5, loose: different enough that you should pick on purpose. Blueberry is noticeably lighter, more muted, warmer than Character Blue.

Can I use Blueberry instead of Character Blue?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Blueberry is noticeably lighter, more muted, warmer than Character Blue.

Can I use Character Blue instead of Blueberry?

The same difference applies the other way round: Character 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.