Using the same principle as my QPlatinum color changing script, I have created a port (or semi-port, at least) of the KDE3 Quartz window decoration style to emerald. Unlike that theme, however, this one is not affected by the smaragd bug that renders the title pixmap incorrectly (because it has no title pixmap). Therefore, it works just fine to use it with kwin (that's actually the reason why I made it).
It isn't a perfect copy of Quartz, because quartz is a hardcoded theme that uses both the blend color as well as the titlebar color to define its colors (at least that's what it seemed like when I was messing around with it in a VM with Trinity Desktop Environment). This one only uses one color (because anything more complex than that would be above my skill level, and might not work with emerald, anyway. I don't really know). I think it still does a pretty good job of capturing the look of the theme. Probably won't work with dark colors, though.
I have attached a few demo emerald themes as well as a tarball that contains the script and all necessary files.