My understanding is that all German steel helmets were issued to the troops painted in 'field grey' which varied from blue-grey to grey-green. However, the troops were then issued with paints in which to paint their own helmets the colours depending on the natural colours of the terrain on that segment of the front. Units tended to have a similar design within the unit but different units could vary markedly. I have not seen this scheme but knowing Trophy it is likely to have some basis in fact albeit the original photos would be in black and white and the exact colours are probably conjectural.

This same practice was implemented in the painting of vehicles and guns hence the great variety of camouflage schemes seen in the German Army of WWI.