/* フォルダペインの未読メッセージを赤色（#ff0033）で表示する　RedやBlue等の色名でも可 */
/* single folder with unread messages */
#folderTree > treechildren::-moz-tree-cell-text(hasUnreadMessages-true) {
  color: #ff0033 !important;
}
/* closed folder containing subfolder with unread messages */
#folderTree > treechildren::-moz-tree-cell-text(closed, subfoldersHaveUnreadMessages-true) {
  color: #ff0033 !important;
}
   
/* open folder containing subfolder with unread messages */
#folderTree > treechildren::-moz-tree-cell-text(subfoldersHaveUnreadMessages-true) {
  color: #ff0033 !important;
}