Southern writes:  

Use the controls below to change the color of your HTML scrollbars for Internet Explorer.
Enter your colors in hex format, e.g. "FF0033" or click the color chip for a popup color picker.
The CSS for the scrollbars that you create is displayed automatically below. Copy it into your HTML page to easily change the scrollbars for your website.
Note: Firefox doesn't support colored scrollbars and the tool won't appear.
CSS ScrollbarNote:
Admin - The reason FireFox (and just about any other browser than IE) does not support messing with the scrollbar is that FireFox attempts to be 100% standards compliant. IE 5.5 (and later) support non-standard CSS properties (and other properties) to alter the appearance of scrollbars. Designers really should not touch a scrollbar's appearance as it's actually a part of the User Interface (UI) and, therefore, poses usability problems. Scrollbars are really not a part of the canvas that designers should have influence over.