[Jenta]

note sure what u mean by FORM background
but if ur talking the grayish areas that dont seem to match

in template shoutbox_iframe look for...

$headinclude
<style type="text/css">
<!--
body {
margin: 0px 0px 0px 0px;
}
</style>
</head>

change it to

$headinclude
<style type="text/css">
<!--
body {
margin: 0px 0px 0px 0px;
background-color: WHATEVER COLOR YOU WANT; <--- new line (remove this part and put a color code there!)
}
</style>
</head>

also there is a missing closing style comment tag there so change it to
example...

$headinclude
<style type="text/css">
<!--
body {
margin: 0px 0px 0px 0px;
background-color: #000000;
}
//-->
</style>
</head>