@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);

treechildren::-moz-tree-row(even) {
  background: #ddd;
  color:#99FF99;
}

treechildren::-moz-tree-row(odd) {
  background-color: #eee;
  color:#99FFFF;
}

treechildren:-moz-tree-row(selected) {
  background-color: royalblue  !important
}