Quick look at a pair of Luftwaffe Adler rings. The black one I was lucky enough to obtain recently from Gaspare. They are both brass with enamel around the Luftwaffe eagle. They're well-worn with a couple of scratches/cracks or chips in the enamel but generally in decent condition.
Black signified Air Ministry staff or engineer. Golden yellow was either for pilots or other aircrew (Fliegertruppe) or parachutists (Fallschirmtruppe). (Note that the GDC 'Waffenfarbe Guide says that yellow was not used in the Luftwaffe, but that is not true.)
Odal posted a yellow ring of the same type a few years ago:
https://forum.germandaggers.com/ubbthreads.php?ubb=showflat&Number=295884#Post295884Does anyone have one of these in a different colour? There was a red (anti-aircraft personnel) and maybe also a blue (medical corps).