Revlon Whimsical is a sheer light blue base with copper and blue glitter. In other words, a dead-on dupe for Deborah Lippmann's Glitter In The Air (at a fraction of the price, thankfully). I also picked this up in the US as it doesn't seem to be available in Europe - I haven't been able to spot it anywhere at least. For it's first outing I wore two coats over Essence You Belong To Me (creepy name much?), a Tiffany box blue.
In future, I'll probably wear it over a nude or lighter shade to really let the blue glitter show but I'm already a fan. I also picked up Popular by Revlon which is along the same lines as this polish, with a pale milky pink base and subtle shimmer that I would also highly recommend.