RLM 81 Version 1 vs Death Korps Drab

How close are they?

ΔE 8.4, close: similar, with a visible difference side by side. Death Korps Drab is more saturated than RLM 81 Version 1.

Can I use Death Korps Drab instead of RLM 81 Version 1?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Death Korps Drab is more saturated than RLM 81 Version 1.

Can I use RLM 81 Version 1 instead of Death Korps Drab?

The same difference applies the other way round: RLM 81 Version 1 is more muted.

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.