Alpha Blue vs Azurite Hue

How close are they?

ΔE 16.2, loose: different enough that you should pick on purpose. Azurite Hue is noticeably darker, cooler than Alpha Blue.

Can I use Azurite Hue instead of Alpha Blue?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Azurite Hue is noticeably darker, cooler than Alpha Blue.

Can I use Alpha Blue instead of Azurite Hue?

The same difference applies the other way round: Alpha Blue is noticeably lighter, 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.