Go to dashboard -> apperance -> theme options -> design-options -> custum css and add the following css there. Hope this helps you
#access a:hover,
#access ul li.current-menu-item a,
#access ul li.current_page_ancestor a,
#access ul li.current-menu-ancestor a,
#access ul li.current_page_item a,
#access ul li:hover > a {
color: #FF0000;
}
.
.