Colorize each tab by the protocol/domain of its content.

domainColorTab.ubiq.js

// Colors each tab by the domain of its content.
// original: http://d.hatena.ne.jp/Griever/20081213/1229155926
const DCT_Palette = let(c = '8ace')(
  ['#'+r+g+b for each(r in c) for each(g in c) for each(b in c)]);
function pageLoad_domainColorTab(doc){
  var [dom] = /^\w+:[\/]*[^\/]+/(doc.location.href) || 0;
  if(!dom) return;
  var tbb, idx = -1, nmr = (Cc['@mozilla.org/appshell/window-mediator;1']
                            .getService(Ci.nsIWindowMediator)
                            .getEnumerator('navigator:browser'));
  while(idx < 0 && nmr.hasMoreElements()){
    tbb = nmr.getNext().getBrowser();
    idx = tbb.getBrowserIndexForDocument(doc);
  }
  if(idx < 0) return;
  tbb.mTabs[idx].style.backgroundColor = DCT_Palette[
    Array.reduce(dom,
                 function dct_acc(s, c) s + c.charCodeAt(),
                 new Date().getDate())
    % DCT_Palette.length];
}//function cmd_