Raw umber

Brown pigment containing the metal oxides and mangan.  Its name comes from the Italian terra di Ombra the area where the pigment was originally extracted. The original yellow-brown pigment was already used back in the Stone Age for the cave paintings, therefore, i tis one of the first known colours to the human kind. During the early Middle Ages, this colour was not so popular, its usage on a bigger scale was recorded in the Baroque period, for example in the work of Caravaggio and Rembrandt. 

In a German-colour pallet the pigment was used either with chromoxide green as a part of the olive colour, or in its pure form on streaky camouflage (as we can see on Fokkers Dr.I).