When in doubt about nail polish I go with greige.
Butter London has several gorgeous and easy to wear neutral colors. Fash Pack, a dark putty/mushroom keeps that balance between an elegant neutral and an edgy modern high-fashion pick. It belongs in the same family as Chanel Particulier, and in very bright or considerably dark lighting the difference in finish is mostly lost. Particulier is creamy and more opaque, which I usually prefer, but the formula and brush of Butter London give Fash Pack a considerable advantage. There's no doubt about it: Particulier was there first and when applied perfectly is sleeker, but I do a better job with Butter London.
Butter London Fash Pack ($14) is available from Ulta, Nordstrom and butterlondon.com.