Summary

It was a Nightmare..

Instructions

exported as 2 STL's, print first ( white) in white at 0.3mm layer height, print will finish at Z = 0.9
edit 2nd STL (black) so it does not automatically home at the beginning of the print

change filament over from white to black.

home X and Y (do not move Z)
G92 E0 Z0 (sets Z to 0, without moving Z)
then run the print

black will lay down over the white print,

print a pair of hooks, http://www.thingiverse.com/thing:30598 then assemble (i use a soldering iron to melt the hoops of the earrings closed after assembly.

Jack Earrings