Troglodyte Blue vs Spectral Blue

How close are they?

ΔE 8.0, close: similar, with a visible difference side by side. Spectral Blue is more muted, warmer than Troglodyte Blue.

Can I use Spectral Blue instead of Troglodyte Blue?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Spectral Blue is more muted, warmer than Troglodyte Blue.

Can I use Troglodyte Blue instead of Spectral Blue?

The same difference applies the other way round: Troglodyte Blue is more saturated, 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.