Define phone support to take stress of the bands.
Add assembled versions of all variants.

I was tending to test more with the C variant than with A lately. I
realized that just randomly changing variants on the assembled version
would be annoying. It seemed more reasonable to add the others than to
just change. This should also facilitate testing all three variations.
Document and color the new assemblies.

Updated the README.me to cover the new assemblies.
Color the different parts to make assembly easier to see. The colors
are not particularly appealing and input from a few others is definitely
warranted.