Spectral Blue vs Light Blue Green

How close are they?

ΔE 8.2, close: similar, with a visible difference side by side. Light Blue Green is more saturated, cooler than Spectral Blue.

Can I use Light Blue Green instead of Spectral Blue?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Light Blue Green is more saturated, cooler than Spectral Blue.

Can I use Spectral Blue instead of Light Blue Green?

The same difference applies the other way round: Spectral Blue is more muted, 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.