Ocean Blue vs Nocturne Green

How close are they?

ΔE 7.0, close: similar, with a visible difference side by side. Nocturne Green is cooler than Ocean Blue.

Can I use Nocturne Green instead of Ocean Blue?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Nocturne Green is cooler than Ocean Blue.

Can I use Ocean Blue instead of Nocturne Green?

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