metti nel HEAD questo:
<style>
body {
scrollbar-3dlight-color:#FF0000;
scrollbar-highlight-color:#FFFFFF;
scrollbar-face-color:#FFFFFF;
scrollbar-shadow-color:#FFFFFF;
scrollbar-darkshadow-color:#FF0000;
scrollbar-arrow-color:#FF0000;
SCROLLBAR-TRACK-COLOR: #D2F0FF;
scrollbar-base-color:#000000;
}
</style>