This is my code:
<div style="width: 100%; height: 100%; overflow: auto">
cell content
</div>


How do I change the scrollbar to a certain color in that area?

scrollbar-face-color:#ffffff;
scrollbar-highlight-color:#68A4C9;
scrollbar-3dlight-color:#59B2CA;
scrollbar-shadow-color:#6788A9;
scrollbar-darkshadow-color:#2B58A3;
scrollbar-track-color:#ffffff;
scrollbar-arrow-color:#25B8EF

Put this after overflow:auto; and change the colors to your personal preference.

http://www.lissaexplains.com/css.shtml