Flake Your Booty

This is Painted Polish Flake Your Booty (over WnW Black Creme, on the wheel):

This is the only true blue flakie I've ever seen, and you're not likely to be able to get your hands on it, sorry. I'm not an expert on nail-polish ingredients, but as I understand it, old-school flakies like this one are made of small, very thin bits of translucent stuff (I think it's Mylar, or something similar) and for some reason the blue version seems to be much more rare. This was one of those LE polishes that disappeared really, really fast, and so this is probably a true HTF polish - I don't really have many of those.

Here's Painted Polish's website - where I'm pretty sure you will not find it - and here's Simply Nailogical waxing rhapsodic about it.

(This was also in my 2015 favorites.)