RAL 8013 Rotbraun vs Nocturnal Red

How close are they?

ΔE 8.3, close: similar, with a visible difference side by side. Nocturnal Red is a little lighter than RAL 8013 Rotbraun.

Can I use Nocturnal Red instead of RAL 8013 Rotbraun?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Nocturnal Red is a little lighter than RAL 8013 Rotbraun.

Can I use RAL 8013 Rotbraun instead of Nocturnal Red?

The same difference applies the other way round: RAL 8013 Rotbraun is a little darker.

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.