I just bought a Thalia capo in black chrome with the blue abalone inlay:
Expensive, to be sure ($70). But the abalone is a perfect match for the rosette. The capo looks like it was made for my guitar.
If you get one, use the flat insert (C) for classical guitars because of the Rainsong 20" neck radius.
EDIT: Sorry for the hugeness of the image. Anyone know how I can fix that?