DataTrigger on Enums as the trigger value on a WPF Style
I have found the solution and it was quite silly.
Styles are designed as a sort of visual template for a control, but they are designed as a base for visual implementation, not as a be-all/end-all visual model.
As a result, I had a situation in which my template dictated what the InnerGlowColor should be. However, by applying the attribute InnerGlowColor="Teal" to the element, I've created an override in effect, ignoring my visual style. The solution was to simply remove the dependancy property in the element declaration.