scrollbar-track-color: Scrollbalken-Hintergrundfarbe (Standards-Mode)

<style type="text/css">
html{scrollbar-track-color:orange;}
body{scrollbar-track-color:red;}
textarea{scrollbar-track-color:blue;}
div{
scrollbar-track-color:green;
overflow:scroll;
width:200px;height:150px;
border:1px solid red;
}
</style>

...

<body>
 <form action="formular.php">
  <textarea rows="10" cols="40">
   Beispieltext
  </textarea>
 </form>
 <div>div-Container</div>

div-Container