Disclaimer: I have worked in Law Enforcement for a local municipality.

The Polizei were likely only interested in what (if any), your slightly different appearance may or may not have to their efforts to maintain the peace. In most communities that I have visited, it is comforting to be noticed by the polizei. I lived for three years in Germany. The polizei stopped me a few times, while I was kilted. The questioning was friendly. On two occasions, the officer that spoke with me advised me of potential problems that I should avoid if possible. I was in the U.S. Air Force at the time, stationed in an occupational role, as were troops from Canada, and the United Kingdom. It seems that some U.K. Troops had gotten into a fracas with some of the locals. The officer was kind enough to give me some advise on what to avoid so as not to be mistaken for the group that had recently committed the offense.
On occasion I have spoken with people, who by their initial appearance stand out from the crowd. The purpose is to find out if I should be nearby if a conflict seems to be possible. This always seems to be oriented to the local alcoholic beverage consumption facilities closing time.
I would take it as official friendly contact.

--- Steve