ΔE 10.2, fair: the same colour family, but not a straight swap. German Grey is a little lighter, more muted than 3B AU/ZB AU.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). German Grey is a little lighter, more muted than 3B AU/ZB AU.
The same difference applies the other way round: 3B AU/ZB AU is a little darker, more saturated.
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 3B AU/ZB AU on the colour wheel See German Grey on the colour wheel
All matches: 3B AU/ZB AU equivalents · German Grey equivalents