ΔE 6.4, close: similar, with a visible difference side by side. Dark Prussian Blue is warmer than Deep Grey.
Usually, if you are not matching paint already on the model. Close match (ΔE 6). Dark Prussian Blue is warmer than Deep Grey.
The same difference applies the other way round: Deep Grey is 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 Deep Grey on the colour wheel See Dark Prussian Blue on the colour wheel
All matches: Deep Grey equivalents · Dark Prussian Blue equivalents