Using Style Manager
Style Manager is a simple yet powerfull tool to centralize your UI setting configs so that you can reskin and tune easily your entire UI without having to dig inside hundreds of widget.
To create a new style just create a new data asset by right clicking in content browser -> Miscellaneous -> DataAsset and select AUTThemeDataAsset. (This will be probably added in the menu to make things easier)
Inside the data asset you can configure all your basic items including:
ANS_Buttons
ANS_Text
ANS_Sliders
ANS_Combo Boxes
AUT_Backgrounds
ANS_Checkboxes
and more
All the base widget inside the tool support Style manager natively, for every item type you can define multiple stiles.
To assign the style to a widget you only need to enable the system in the widget itself and assign the related style and it will automatically reskin.
Custom Widget in Style Manager
The easiest way to integrate a custom widget in to the Style Manager, would be creating a child class of ANSNavWidget and simply implement the UpdateStyle function, a sample from the ANSButton: