Certainly black. The Bundeswehr uniform is gray and has been since reconstitution after the war. Feld Grau is the traditional color of German uniforms since before WWI.Think about all the fashion aspects that typically aren't reproduced for fear of inappropriate imagery:
Double breasted uniforms, unless offset to the side
Capes
Gorgets
Arm bands
Chrome buttons
Oversized Plackets or teardropped plackets
Black / grey uniforms
Black / Silver piping
Armored cavalry uniforms that look like cavalry uniforms
Ribbons/Medals as ties
Lapel patches
