I Love Nail Polish- Sirene is from the Spring 2014 collection of Ultra Chromes. The other one that I picked up from the same set is Nostalgia (H), swatched here.
Sirene is a gorgeous green/ aqua/ indigo/ purple multichrome. Straight-on it appears mostly vibrant green with teal/aqua and indigo fading out toward the edges. At more oblique angles, it is purple/ indigo.
Artificial light, two coats:
If you don't like green on your nails at all, you won't like this- but, it really is super changeable, and if you like multichromes, you need Sirene. It's beetles on your nails!
Formula: It applies sheerly, but is not streaky. It sort of wants to drag baldish patches if you overwork an area, but then if you wait long enough, it self-levels to correct it. The second, slightly thicker, coat is opaque, if a little thin at the tips. Brushstrokes are invisible at normal viewing distances. Very nice!