Good job on the hinges! The materials used do vary, the newer material are cheaper in price and quality. Plastics used on eyeglasses that have more substance is called Zyl and the temples usually have a wire running thru them to add adjust-ability and firmness, the wire is about as thick as a coat hanger. Frames made of Zyl are heatable and resilient, we heat the frame to snap in the lenses and the material takes the contours and cools down, locking the lenses inside the frame, there are safety consequences to loose lenses. We use hot air or a heating pan with table salt or glass beads to stretch and adjust frames.
You can use RIT dye heated to just below boiling to color your clear frames. The material will probably absorb into the frames. It is more of a translucent coloring but it is a nice and cheap way to get a little more diversity. Better quality frames have a clear frame protective coating to keep the material looking new, kind of like a clear coat on your car. The coating will help preserve your coloring and lock in any leaching the materials you are using.
This is the future, people will down load frames designs and print out frames saving lots of money, Prada anyone?