I have added a section from an interview with FHvD on sound, set design and colour below.
What was your approach with respect to sound, set design and colour schemes?
To capture the atmosphere of East Berlin, we did not record in digital but in analogue in order to convey a sense of “reduced calm.” Set designer Silke Buhr and I had a very definite idea about the colour scheme. The GDR had its own world of colours and forms. The cars and fabrics were pale and desaturated. We proceeded through reduction. Since there was more green than blue in the GDR, we completely omitted blue. There was also more orange than red, so we eliminated red. We consistently used certain shades of brown, beige, orange, green and grey to try and be as authentic as possible to what life under the GDR looked like. Emptiness is an aesthetically neutral condition. The streets of East Berlin are filmed almost empty, exactly as they were during those years. The local Kneipe, or pub, is almost empty; the canteen for the Stasi employees is Spartan. Wiesler’s apartment, a “plattenbau” (or high-rise apartment the Communists built during the 70s) is devoid of any sense of being a home. Wiesler’s world actually starts to open when he begins spying on the actors who live in a charming Altbau, a typical old Berlin apartment with big rooms, high ceilings and creaky wooden floors. When he is perched above their apartment, using the attic as his listening post, I wanted to convey that his worldview was challenged. We did not want an overload of “GDR props.” For me, the set design has to deliver the perfect background for the emotions of the actors – no more, but also no less. I don’t want the viewer to start thinking about individual props instead of emotionally connecting with the characters.