Dunkelgrau RAL 7021 vs Corvus Black

How close are they?

ΔE 8.2, close: similar, with a visible difference side by side. Corvus Black is a little darker than Dunkelgrau RAL 7021.

Can I use Corvus Black instead of Dunkelgrau RAL 7021?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Corvus Black is a little darker than Dunkelgrau RAL 7021.

Can I use Dunkelgrau RAL 7021 instead of Corvus Black?

The same difference applies the other way round: Dunkelgrau RAL 7021 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.