Please excuse the boo-boo on my ring finger.
I've done this combination before: one coat of Wet 'n Wild Nocturnal, one coat of Sally Hansen Laser, and one coat of Sally Hansen Spectrum. Nocturnal is a dark, dark blue that's practically black. Laser is a duochromy blue-pink glass fleck. Spectrum has the same effect as Laser, except it goes from turquoise to pink. And of course, there is a generous coat of Seche Vite over the entire thing.
This is like ... my go-to combination when I don't have the creativity to think of something else.
Oh, I bought some new China Glaze Crackle Glazes, so I'll be posting a picture of my nails with that ... in a few days. Haha.