@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);
.tabbrowser-tab[selected="true"]{
  background-color: #B83E3B !important;
  color: #fff !important;
}
.tabbrowser-tab[selected="true"]:hover{
  background-color: #CB6161 !important;
  color: #fff !important;
}