Leaf Green vs Death Korps Drab

How close are they?

ΔE 7.5, close: similar, with a visible difference side by side. Death Korps Drab is a little darker than Leaf Green.

Can I use Death Korps Drab instead of Leaf Green?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Death Korps Drab is a little darker than Leaf Green.

Can I use Leaf Green instead of Death Korps Drab?

The same difference applies the other way round: Leaf Green 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.