ΔE 7.2, close: similar, with a visible difference side by side. Dark Prussian Blue is a little lighter, warmer than Ocean Blue.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Dark Prussian Blue is a little lighter, warmer than Ocean Blue.
The same difference applies the other way round: Ocean Blue is a little darker, 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.
See Ocean Blue on the colour wheel See Dark Prussian Blue on the colour wheel
All matches: Ocean Blue equivalents · Dark Prussian Blue equivalents