To remove yellow background for the menu buttons please add this code into custom.css file: #main-nav .current-menu-item a, .menu .current-menu-item a {background: none repeat scroll 0% 0% !important;}
To create custom.css you need rename default.custom.css file to custom.css that is located in wp-content/themes directory via FTP. Then enable it in Theme Settings > tick “Enable Custom CSS”.
