FireFox - Color/Highlight The Active Tab

If you want the active tab to stand out in your current tab exactly like below:

Then edit your userChrome.css file located in your profile folder and add the following lines:

tab[selected="true"] {
  background-color: rgb(205,69,50) !important;
  color: black !important;
}

tab {
  -moz-appearance: none !important;
}