These colours are not available any more, but Caitlin has done clear-outs of leftover Colour of the Month stock before, so I thought I'd swatch them anyway. FOR SCIENCE.
Nestyr was the 3rd birthday shade. "Beautiful incandescent soft purple glowing with green, gold, and red duochrome."
This is a really pretty colour, but the only shimmer I see is green, which means it's a dupe or at least very similar to a couple other colours I have. There's a bit of red visible in direct sunlight, but it's very subtle.
Purple with green (or blue) iridescence is one of my weaknesses and seems to be a popular colour for indies to produce (not that I'm complaining!) Herbivore from Fyrinnae, Dulcinea from Aromaleigh and Hummingbird from Sobe Botanicals come to mind. I'll do a comparison post later on.
Butts was the Colour of the Month for July. "A smooth golden yellow-khaki with soft velvety shimmer."
I really like this because 1) Malcolm Reynold's butt and 2) it's a really smooth, satiny gold-toned khaki. Makes an excellent lid colour for my olive-y skin, and I can see it being stunning against dark skin, and a great outer corner/crease colour for pale people.
Have you picked up any of the Colour of the Month eyeshadows from Shiro? This brings me up to three and I really like all of them. My first was Dance of Death swatched here.