To change the color of the text area of the TimePicker you have to edit its template. In order to do that you can edit the TimePicker in Blend Expression. Right click on the control, choose from the menu Edit Template -> Edit a Copy. Blend will generate for you the style for the TimePicker.
Attached you will find a sample project in which that is illustrated. Please mind for the "NOTE:" comments which point the place where you have to make changes.
If you have further questions please feel free to contact us again.
Best wishes,
Konstantina
the Telerik team
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