When bulk editing and publishing TFS workitems in Excel using integration provided by Visual Studio 2012 - when workitem has invalid fields - the work item editing control can be opened to fix the errors. The control has similar, but not exact same colors as Visual Studio 2012 light theme. Thus controls currently disabled lack borders since it seems border color is same as form background color. Also titles are black - when in light theme they are dim gray. Also regardless of theme selected in Visual Studio - the control opened from excel has "light" appearance.