background: yellow;
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns='http://www.w3.org/1999/xhtml' xml:lang='en'> <head> <title>background</title> <style type='text/css'> p { clear: left; } div { border: 1px solid yellow; width: 100px; height: 100px; margin: 10px; float: left; } div#background-color { background: yellow; } </style> </head> <body> <div id='background-color'> </div> </body> </html>