Looks like a style inside the dropdown menu plugin you have installed.
This is the CSS setting the text to white:
li.current-cat a, li.current_page_item a, li.current-menu-item a, li.current-cat a:link, li.current_page_item a:link, li.current-menu-item a:link, li.current-cat a:visited, li.current_page_item a:visited, li.current-menu-item a:visited {
color:#FFF;
}If you change that color by adding the above to your CSS and changing the hex, it should work.