ΔE 6.7, close: similar, with a visible difference side by side. BC Dark Brown is a little lighter than Waffen Brown.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). BC Dark Brown is a little lighter than Waffen Brown.
The same difference applies the other way round: Waffen 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.
See Waffen Brown on the colour wheel See BC Dark Brown on the colour wheel
All matches: Waffen Brown equivalents · BC Dark Brown equivalents