ΔE 18.5, loose: different enough that you should pick on purpose. Blue is noticeably darker, much more saturated than Alpha Blue.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Blue is noticeably darker, much more saturated than Alpha Blue.
The same difference applies the other way round: Alpha Blue is noticeably lighter, much more muted.
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 Alpha Blue on the colour wheel See Blue on the colour wheel
All matches: Alpha Blue equivalents · Blue equivalents