RAL 7008 Graugrün vs Desert Yellow

How close are they?

ΔE 8.2, close: similar, with a visible difference side by side. Desert Yellow is more saturated, warmer than RAL 7008 Graugrün.

Can I use Desert Yellow instead of RAL 7008 Graugrün?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Desert Yellow is more saturated, warmer than RAL 7008 Graugrün.

Can I use RAL 7008 Graugrün instead of Desert Yellow?

The same difference applies the other way round: RAL 7008 Graugrün is more muted, 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.