As far as I know, between 1919 and 1958, there was no such thing as German naval infantry (discounting infantry formations assembled during WW2 from sailors).
Given the low personnel strength of IIRC 15.000, the Reichsmarine focused on creating high-quality ship crews and supporting structures; since an actual use of the Reichsmarine apart from the tasks accorded to it in the Versailles treaty (mainly coastal security in the Baltic and North Sea) was rather unlikely, naval infantry for landing operations were not strictly necessary.
Several of the German larger surface combatants (Emden II, in particular) undertook some PR and training world circumnavigations. In those cases, I think ratings and officers just wore white summer service dress when in tropical waters. My books on the subject are in storage in Germany at the moment, but I seem to recall some photographs of white-dressed sailors in South America.