Forum Moderators: open
Yes, this can be done. But, it would only work in standards compliant browsers. And, since IE is not standards compliant while being the only browser that lets you style the scrollbars (unless you've specifically changed your settings in Opera, for example) I think you're at a dead end.
Also, you can only change scrollbars on child elements. There is, for example, no way of saying "when I hover this element, make the body's scrollbars change color". The element with the scrollbar must be a child/sibling to the current element.
<div> <!-- parent / container -->
<span></span> <!-- child / nest -->
</div>
A sibling element 'lives' next to another element (it's previous and next 'siblings'), like...
<div></div> <!-- sibling -->
<span></span> <!-- sibling -->
Jordan