Hey, supercool!! .... love this kind of thing.
The reason your pieces darkened can be one of several:
...
Sculpey brand clays (original Sculpey, SuperSculpey, Sculpey III) darken more easily than other brands. This is particularly true for their lighter colors or any colors with translucent in them (which can include even the dark colors)
...
miniatures like these don't need as
long a bake as regular size items... theoretically, all clays but those Sculpeys could stay in the proper temperature for hours and hours and never darken, but it can be hard to make sure the temp
never gets higher; next time try only about ten minutes
...
temperature in the oven, or next to the clay, can be hotter than you think
.....unless you measured the temp with a separate oven thermometer, it may not actually be the same temp that the dial is indicating
.....you may have baked on something which will heat up more than the ambient temperature in the oven, like metal or ceramic tile
.....your item may be too close to the bottom coils or to the sides of a small oven, or even in a "hot spot"
There are ways to avoid all these problems though. Check out my page on baking polymer clay for loads of info about all of them:
http://www.glassattic.com/polymer/baking.htmI wish the polymer clay "microorganism" swap was still online for you to see! Turns out there are quite a few scientists and science types involved in polymer clay, and these guys created a swap for items which might be found under the microscope; they were really great!
....There are other people in the science field (including nurses, researchers, etc.) who love various micro-organisms, parameciums, etc....and love to use them as jewerly, pens, etc.
... Once he and I made some pinworms from clay for a "joke" presentation to a research doc. The doc loved them so much they hang right next to his Nobel Prize!!! syndee
...sanguinia's polymer clay maggot or grub (as pendant)... made out of translucent clay with a dab of ivory clay (roll into a thick snake and then start twisting. ...smooth off the "head" part, and pierce a hole through it side to side....bake) ... I also made a "lovely larva" too using some orangey-brown and ivory clay.
...great bugs:
http://www.pbase.com/joanie/bugz (4 pages)
http://groups.msn.com/ALANMARY/shoebox.msnw (there are many more polymer bugs on this page as well:
http://www.glassattic.com/polymer/kids_beginners.htm.......click on
Animals, then scroll down to the
Bugs section)
...my son just made a good-sized brain from polymer clay for a school project... it had many of the various parts in different colors, then he sat the whole thing in the top of a plastic Halloween skull as his "presentation". Diane B.
For more polymer clay body parts, you might want to check out these pages at my site:
http://www.glassattic.com/polymer/Halloween_etc.htm(...click esp. on
Things in a Bottle + Eyeballs...)
http://www.glassattic.com/polymer/sculpting_body_and_tools.htm(....click on
various body parts, though not many are "interior" parts...)
Diane B.
--- polymer clay "encyclopedia"
http://www.glassattic.com/polymer/contents.htm 
