I know that B&W was used to give the film a WWII-era look, but I think it was a mistake. "Gone With The Wind (1939)", a film depicting an era 80 years prior to WWII was deliberately produced in color to add emphasis, and I seriously doubt the award count would have been as high in B&W. Mountain Man
The reason they used B&W was because you couldn't "buy into" the movie if it was in color. The script was HUGELY melodramatic. You might not think it judging by the average summer blockbuster, but by and large today's movie going audience is more sophisticated than previous generations, especially in cinema's early years. Even if you think a movie like Casablanca is an unassailable classic, ask yourself what the movie would be like if it were shot in color and with a modern cast but with the exact same script. It just wouldn't work. It's too over the top. The dialog is dated and corny in places.
The Good German is a bad script by modern screen writing standards. Shooting it in black and white and pretending that the movie is not just set in the past, but actually a throwback to those old movies, is an attempt to obscure that fact. In my opinion, it didn't work.
Orgies are not too much fun if no one wants to do it with you.