I consider it a yeshivishe color, & totally ok.
Of course its not your typical Sem girl color,
or mainstream chareidi, it seems kind of funny though cuz
everything else is so black about the way our chareidim women(& men) dress i.e. tops, skirts, dresses,socks, etc..
why not black polish?
As long as the rest of the outfit is tznius,& doesn’t scream
Punk, or Machsefa, I don’t see the problem.