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

.tabbrowser-tab[selected="true"],
.tabs-bottom,
[class="close-button tabs-closebutton"] {
  background-color: blue !important;
}

.tabbrowser-tab[selected="true"] .tab-text {
  color: white !important;
  -moz-opacity: .85 !important;
}

.tabbrowser-tab[selected="true"]:hover .tab-text {
  -moz-opacity: 1 !important;
}