It is possible. You just should set the same Brush from Office2013Palette
which is used for the Header of the DatePicker. In this case it is the AccentBrush
, so you can just set the following:
More about the Office2013 theme and its Palette you can find in our help topic Office2013 Theme
. As for the brushes of the controls and their styles and templates you can check them in the Themes.Implicit.sln
which is in the Telerik Controls Installation folder.
So, back to your case - you can edit the control template
of the RadExpander and add a Border in the Header with the desired Background:
For your convenience I implemented this approach in the attached project. You can take a look at it and let us know if it works for you. Please have in mind that the Background of the ToggleButton in Pressed state will be the same as the Header Background of the Expander, so maybe you should consider some changes.
I hope this information will help you and don't hesitate to write back if you have more questions.