Jennifer,
The symbol is just a simple polygon fill that is rendered from a dynamic feature service. It is actually built from an SDE feature, not gdb. It is about as basic as you can get, a feature service with a simple polygon fill with the transparency set to 30%. If I set the transparency in the service, it does not render transparent on the map. If I set the transparency in the xaml, then it will render transparent, but the clone is not transparent while editing.
Does the rest endpoint support transparency in a feature layer?
Thanks, Chris