Azure Magic vs Sparkling Blue

How close are they?

ΔE 23.1, loose: different enough that you should pick on purpose. Sparkling Blue is noticeably lighter, cooler than Azure Magic.

Can I use Sparkling Blue instead of Azure Magic?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 23). Sparkling Blue is noticeably lighter, cooler than Azure Magic.

Can I use Azure Magic instead of Sparkling Blue?

The same difference applies the other way round: Azure Magic is noticeably darker, 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.