User blog comment:Dopp/Meet the Mini Editor/@comment-1017446-20120323011240/@comment-1393830-20120323011742

.MiniEditor #WikiaArticleComments .MiniEditorWrapper .editarea textarea { background-color: white; color:black; }

If you put the above in your wikia.css file on your wiki, it will change the text area to be white with black text.