Web sites can configure the directory path containing their style set files application-wide by using the styleSetPath attribute of their "web.config" file. It is also possible to configure the style set path applicable to all controls on a Page that are subject to Application Styling by placing a WebPageStyler control on that Page and setting it's StyleSetPath property.
At the control level this property allows an application developer to customize the location of the style set being applied to a single instance of a control.
Be aware that customizing the style set path at the control level will not allow you to copy a style set's files to this new location, changing a few style property values in them, and then use it successfully with separate instances of the control referencing the original style set of the same name. This is because there would be naming collisions in the Cascading Style Sheet (CSS) class names, which will produce an undefined appearance. You must ensure the CSS class names defined by style sheets in the new style set path are unique from those CSS class names being used by other style sheets that may continue to be referenced. The recommended guidance in this scenario is to create a new style set having a new style set name, that contains your modifications.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2