ΔE 8.5, close: similar, with a visible difference side by side. Ocean Gray is a little lighter, cooler than Cobalt Violet Grey.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Ocean Gray is a little lighter, cooler than Cobalt Violet Grey.
The same difference applies the other way round: Cobalt Violet Grey is a little darker, 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.
See Cobalt Violet Grey on the colour wheel See Ocean Gray on the colour wheel
All matches: Cobalt Violet Grey equivalents · Ocean Gray equivalents