Ocean Grey vs Faded P.R.U. Blue

How close are they?

ΔE 6.3, close: similar, with a visible difference side by side. Faded P.R.U. Blue is a little darker than Ocean Grey.

Can I use Faded P.R.U. Blue instead of Ocean Grey?

Usually, if you are not matching paint already on the model. Close match (ΔE 6). Faded P.R.U. Blue is a little darker than Ocean Grey.

Can I use Ocean Grey instead of Faded P.R.U. Blue?

The same difference applies the other way round: Ocean Grey is a little lighter.

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.