The German military uses insignia piped in different colors (known as Waffenfarbe) to distinguish different service branches. In WWII, the Wehrmacht used shoulder board insignia as the only distinguishing unit insignia for most units. This original 1944 German document from the US National Archives indicates the correct Waffenfarbe and shoulder board insignia for every type of unit in the German Feldheer.
“Übersicht der Truppenkennzeichen des Feldheeres”
