They're made by somatic glass, so almost any of their colours can be used (ah, two tone <3)
http://somaticglass.com/jewelry/
And they can order more colours too. I was looking through their supplier, soooo many colours!
Teallusion is probably one of my faves (looks nothing like the pic), as well as amber/purple (and that funny alien looking one I've seen a few people use. But I'm not sure Somatic use that)