Nocturne Green vs Templar Blue

How close are they?

ΔE 6.2, close: similar, with a visible difference side by side. Templar Blue is more muted than Nocturne Green.

Can I use Templar Blue instead of Nocturne Green?

Usually, if you are not matching paint already on the model. Close match (ΔE 6). Templar Blue is more muted than Nocturne Green.

Can I use Nocturne Green instead of Templar Blue?

The same difference applies the other way round: Nocturne Green is 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.