Dark Brown vs German Red Brown

How close are they?

ΔE 7.5, close: similar, with a visible difference side by side. German Red Brown is a little lighter than Dark Brown.

Can I use German Red Brown instead of Dark Brown?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). German Red Brown is a little lighter than Dark Brown.

Can I use Dark Brown instead of German Red Brown?

The same difference applies the other way round: Dark Brown 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.