Light Metallic Blue vs Sapphire Blue

How close are they?

ΔE 8.1, close: similar, with a visible difference side by side. Sapphire Blue is warmer than Light Metallic Blue.

Can I use Sapphire Blue instead of Light Metallic Blue?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Sapphire Blue is warmer than Light Metallic Blue.

Can I use Light Metallic Blue instead of Sapphire Blue?

The same difference applies the other way round: Light Metallic Blue is 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.