When you put a border around your entry date boxes, can you put a white background to it?

<style type="text/css">
div.blogheader, .caption {
/* edits the dates */
font-family: arial;
text-transform: lowercase;
font-size: 15px;
color: #cc0000;
letter-spacing: 0px;
text-align: right;
width: 380px;
border: 1px solid #000000
}
</style>

That's the code that I have, but can I put a white background to it?
Thanks

<style type="text/css">
div.blogheader, .caption {
/* edits the dates */
font-family: arial;
text-transform: lowercase;
font-size: 15px;
color: #cc0000;
letter-spacing: 0px;
text-align: right;
width: 380px;
border: 1px solid #000000;
background-color: #FFFFFF;}
</style>