(can you believe that last pic is of the same polish?!)
this is one coat of turquoise opal over one coat of wet 'n' wild black creme. bc is such a pain to use, thanks to its horribly floppy and imprecise brush, but i've been using it for layering 'cause i'm hesitant to overuse my booooooooosh lest i run out. i should've bought nine million boosh backups during sephora f&f!
i hate to tag turquoise opal as a duochrome when it actually flashes teal, red-purple, lilac, blue, and on very rare occasions (like for half a second under my desk lamp last night), amber-gold... a very unique polish. it's a little frosty for my taste at times, but once it starts flashing all these amazing (and seemingly unrelated) colors, its frostiness becomes a non-issue in my mind.
bf says: "that's the t-1000 of nail polishes... it's ever-shifting!"