I recently saw the film Alone in Berlin starring Emma Thompson and Brendan Gleeson. It is a fictionalised account of the novel Every man dies alone by Hans Fallada, based on the true life story of Otto and Elise Hempel.
The Hempels, having lost their only child, their son Hans, in combat, in grief and desperation conduct a hopeless personal campaign against the Nazi state.
The film is an excellent period drama, and went to some length to provide authenticity of 1940s surroundings, in street, public environment, and domestic scenery.
During the course of the film two different police forces are involved - regular plain clothes police, and the SS. (It did seem surprising that the SS would have been messing with such relatively small-time dissent. I would have expected investigations to have been overseen by the Gestapo.) However the SS officers were not wearing their characteristic black uniforms, but grey-blue tunics and darkish trousers. To me this seemed more to resemble the Wehrmacht uniform.
Is there a historian of Nazi Germany who might be able to explain why the Gestapo would not have been involved, and why the SS were not wearing black tunics?