Yes WinnieThePooh’s thread link for a nail polish color discussion.
Again this one:
http://www.theyeshivaworld.com/coffeeroom/topic/tznius-5
I could be wrong but I think even commonly-recognized tznius nail polish colors may not be tznius in some communities.
Some tznius minhagim are community-specific so it’s a question that depends on where you live in addition to further factors.
Please ask your LOR for more info.