mdserver-web/plugins/data_query/static/css/ico.css

/* menu start  */
.menu .current .menu_plugin_data_query:hover {
    background-image: url("/plugins/file?name=data_query&f=ico.png");
}

.menu .menu_plugin_data_query {
    background-image: url("/plugins/file?name=data_query&f=ico.png");
}

/* menu end  */