ΔE 8.8, close: similar, with a visible difference side by side. Doombull Brown is a little darker, more muted, cooler than RAL 8012 Rotbraun.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Doombull Brown is a little darker, more muted, cooler than RAL 8012 Rotbraun.
The same difference applies the other way round: RAL 8012 Rotbraun is a little lighter, more saturated, 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 RAL 8012 Rotbraun on the colour wheel See Doombull Brown on the colour wheel
All matches: RAL 8012 Rotbraun equivalents · Doombull Brown equivalents