Scrollbars are not part of the DOM tree, so in genral they should not be styled with CSS. Even if we provide such a behavior with RadFromDecorator for Internet Explorer and Webkit browsers, it is still deprecated, as it is considered as a User Interface violation, bacause the scrollbars are part of the Web Browser interface, and not part of the web site.
I have tried to style a little the scrollbars in IE, but we could only change some basic color, and not the shape and size of the up/down/left/right arrows.
the Telerik team
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