body#tinymce.wp-editor.content {
  background-color: #fff !important;
  color:#000 !important;
}
body#tinymce.wp-editor.content a, 
body#tinymce.wp-editor.content a:hover, 
body#tinymce.wp-editor.content a:active {
  color:#000 !important;
  text-decoration: underline !important;
}