So I was watching that sketch (you all know which) about German soldiers wondering if they were the bad guys and it got me thinking. German officer uniforms were generally black or dark grey, many of the regular uniforms were similar colors, skulls were popular imagery, and red and black were the colors of the flag and generally brought around everywhere.
How come so much of the imagery seems to have been made to be evil? I know that a lot of our perception of what is evil probably stems from WW2, but still, did nobody look at themselves and say "we look like stereotypical evil doers"?
You seem to be referring to the SS in particular here, and even more specifically the SS-Totenkopfverbande, the sub-section of the SS that ran the numerous concentration camps throughout the Reich. They were notorious for having a totenkopf (death's head) insignia on their peaked caps and in cases collar's
What's interesting to note about the SS is that every branch uniforms (with the exception of the Waffen-SS, the armed wing of the SS that modeled it's uniforms after the traditional feldgrau (field gray) of the Wehrmacht) were designed by two SS members (Karl Diebitsch and Walter Heck) but made by none other than Hugo Boss. Whilst they do look rather intimidating, I imagine the intention was to promote professionalism.
In relation to normal German soldiers, whilst the uniforms of the Werhmacht, the Luftwaffe (air force) and Kriegsmarine saw numerous changes under the Nazi regime, in some ways they deviated little from the WW1 uniforms, with the exception of the Luftwaffe who revamped it's uniforms a lot under Gorings insistence. Up until 1942, when camouflage was ordered compulsory to new equipment the feldgrau still persisted with most army units along with the old Stahlhelm helmet.
Whilst it's true to say that we today identify the uniforms (particularly those of the SS) as being blatantly associated with evil, it was mostly viewed by the men who wore them as being smart, professional and indeed even meriting considering the state they served. I invite more knowledgeable redditors to go further into detail as I have been a bit broad. I hope this answered some of your questions
(Sources; The Rise and Fall of the Third Reich by William.L.Shirer)