Mediterranean Blue vs Alaitoc Blue

How close are they?

ΔE 7.6, close: similar, with a visible difference side by side. Alaitoc Blue is a little darker, more muted than Mediterranean Blue.

Can I use Alaitoc Blue instead of Mediterranean Blue?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Alaitoc Blue is a little darker, more muted than Mediterranean Blue.

Can I use Mediterranean Blue instead of Alaitoc Blue?

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

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.