Repro Steps:

1) Grab the Engineering sample, and create a local copy of the project folder for yourself.
2) Create a new ResourceDictionary named 'Colours".
3) Navigate to the ResourcesPanel, and merge the 'Colours' ResourceDictionary into the GlobalDictionary, to make the Colours accessible from anywhere.
4) With the GlobalResources dictionary as the active Page, drag all Colours from the GlobalDictionary into the new Colours.xaml.
5) Return to the MainPage.

Observe how the interface is broken and not displaying the colours it should.
Observe that areas where colours were previously used, have been replaced with 0% opacity blacks.

Expected Results: Moving a Resource from one Dictionary to another should not break the user interface.