[Plugin: Ozh' Admin Drop Down Menu] Feature Request: Tiled Background Image!

This can be done from the theme, though Ozh should probably do it himself as well. The solution is to use a CSS gradient with a fallback to flat gray and completely eliminate the outdated graphic approach.

First, declare an admin stylesheet:

function customAdmin() {
    $url = get_settings('siteurl');
    $url = $url . '/wp-admin.css';
    echo '<!-- custom admin css -->
          <link rel="stylesheet" type="text/css" href="' . $url . '" />
          <!-- /end custom adming css -->';
}
add_action('admin_head', 'customAdmin');

Then add the following CSS definitions:

#ozhmenu {
background: rgb(81,81,81);
background-image: none;
background: url(data:image/svg+xml;base64,PD94bWwgdmVyc2lvbj0iMS4wIiA/Pgo8c3ZnIHhtbG5zPSJod…EiIGhlaWdodD0iMSIgZmlsbD0idXJsKCNncmFkLXVjZ2ctZ2VuZXJhdGVkKSIgLz4KPC9zdmc+);
background: -moz-linear-gradient(top, rgba(81,81,81,1) 0%, rgba(14,14,14,1) 100%);
background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(81,81,81,1)), color-stop(100%,rgba(14,14,14,1)));
background: -webkit-linear-gradient(top, rgba(81,81,81,1) 0%,rgba(14,14,14,1) 100%);
background: -o-linear-gradient(top, rgba(81,81,81,1) 0%,rgba(14,14,14,1) 100%);
background: -ms-linear-gradient(top, rgba(81,81,81,1) 0%,rgba(14,14,14,1) 100%);
background: linear-gradient(to bottom, rgba(81,81,81,1) 0%,rgba(14,14,14,1) 100%);
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#515151', endColorstr='#0e0e0e',GradientType=0 );
border-bottom: 2px solid black;

#ozhmenu img.wp-menu-image {
height: 18px;
}

Ozh may fire its own background second, in which case you will have to use specificity or the !important tag to override it.