Thank you for contacting us and sorry for the delay.
All styles and resources can be found in the Binaries folder in the installation folder of the controls. For each assembly there is a folder named after it that contains a Themes folder with all resources available for this assembly. For NumericBox the default location is:
C:\Program Files (x86)\Telerik\UI for Windows Universal [version
Just put the right version and platform in the path. You will find a Generic.xaml file that contains the default style of the control. You will also have to load the predefined Telerik named resources, you can find more information here: Resolving Telerik named resources
I hope this helps. Please, let us know if you have further questions.
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