It was hard to decide which to swatch first; I eventually chose 504, a purple-based duochrome shimmer. Well, really more like a tri- or quad-chrome; this is one complex polish, so I took lots of pictures.
I first tried it on its own. It's a bit sheer, so I ended up using four coats. It's possible I was subconsciously doing thinner coats than normal, though, in an attempt to use less of this precious polish. This first photo was taken in my lightbox, and you can see just a hint of the color change from brownish red at the tops of my nails to blue purple on the bottom.
Since the sun was actually shining, I moved outdoors for these next pictures, the better to show off the different colors that flash from this polish. I still need lots of practice photographing duochromes but hope you can get some idea of how great this polish is. (I also hope you can ignore the bit of cotton or something that I managed to trap in the polish; I did my best to shoot from angles that didn't make it look like a mountain in the middle of my nail but it's definitely spottable.)
Though I could have stood out on the porch for much longer admiring the pretty colors, I came back in because I wanted to try it layered over black. I used two coats of Rimmel Lycra Wear Black Satin as a base and followed with two coats of 504. (I might have been able to stop at one but thought two would give better depth to the colors.) The black underlayer really brought out the blue in the 504 but didn't interfere at all with the color-changing goodness. (And here I would like you to ignore not only a cotton wisp mountain, but the big smudge I got from moving my fingers around to enjoy the colors before the polish was quite dry.)
This is an awesome polish. I understand it's not overly easy to obtain, even if one is in Australia, and I thank Elizabeth so much for making the effort to get it and its friends to me.