Hi Forum,
due to some limitations in the framework, it is a known issue when applying a theme implict, the background of the application does not get affected properly.
So you have to set the background explicitly!
Here is an example:
...
xmlns:xcpt="clr-namespace:Xceed.Wpf.Themes.Office2007;assembly=Xceed.Wpf.Themes.Office2007.v2.0"
<Menu Background="{x:Static xcpts:Office2007BlueResources.ControlBackgroundBrush}">
...
Don't forget to change all of this references if you want to switch to another theme.
Kind regards,
Torsten