Magic Blue vs Talassar Blue

How close are they?

ΔE 7.8, close: similar, with a visible difference side by side. Talassar Blue is a little darker, warmer than Magic Blue.

Can I use Talassar Blue instead of Magic Blue?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Talassar Blue is a little darker, warmer than Magic Blue.

Can I use Magic Blue instead of Talassar Blue?

The same difference applies the other way round: Magic Blue is a little lighter, 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.