Though I have not found a solution to this problem, I no longer need to know. So can the post be deleted please (unless anyone else is interested)?
answered on 18 Jul 2016, 12:02 PM
As per the Implicit Styles article in our documentation, you can find the XAML files in the local installation of the Telerik controls. The folder Themes contains the different resources for the different themes that you can use in your application. You can have a look at the Template of the GridViewRow element for the theme that you have set. There is a certain border that is applied to the selected item and respectively you can track down the brush that is applied to this specific state.
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