In the past, I tackled this task using Firefox 7. Reflecting on it now reveals numerous issues, but it accomplishes the desired outcome. Nonetheless, enhancements to the code are definitely necessary:

var {Cc, Ci} = require('chrome');
var sss = Cc['@mozilla.org/content/style-sheet-service;1'].getService(Ci.nsIStyleSheetService);
var ios = Cc['@mozilla.org/network/io-service;1'].getService(Ci.nsIIOService);
var windowUtils = require('window-utils');
var wm = Cc['@mozilla.org/appshell/window-mediator;1'].getService(Ci.nsIWindowMediator);

exports.main = function() {
    //no exports required
};

var aWin = wm.getMostRecentWindow('navigator:browser'); //aWin refers to anyWindow used by functions like encodeURI

//hide extended label when page is verified
var identityBoxCss = '.verifiedDomain .plain {display:none}';
var identityBoxCssData = 'data:text/css;charset=utf-8,' + aWin.encodeURI(identityBoxCss);
var identityBoxCssUri = ios.newURI(identityBoxCssData, null, null);
//end hide extended label for verified pages
//colorize URL bar
var gUrlBarColorize = {
    func: function(win) {
        var identityIconLabel = win.document.getElementById('identity-icon-label');
        var identityBox = win.document.getElementById('identity-box');
        var gURLBar = win.gURLBar;
        if (gURLBar.value.search(/https/i) == 0) {
            if ((identityBox.classList.contains('verifiedDomain') || identityBox.classList.contains('verifiedIdentity'))&& identityIconLabel.value.length > 0) {
                gURLBar.style.backgroundColor = '#D0F7B9';
            } else {
                gURLBar.style.backgroundColor = '#F8D6DE';
            }
        } else {
            gURLBar.style.backgroundColor = '';
        }
    }
};
//end - colorize URL bar
//hide icons in bookmarks toolbar
var bookmarksToolbarCss = '.bookmark-item .toolbarbutton-icon {display:none}';
var bookmarksToolbarCssData = 'data:text/css;charset=utf-8,' + aWin.encodeURI(bookmarksToolbarCss);
var bookmarksToolbarCssUri = ios.newURI(bookmarksToolbarCssData, null, null);
//end - hide icons in bookmarks toolbar

var wt = new windowUtils.WindowTracker({
    onTrack: function (window) {
        //hide extended label when page is verified
        var IdentityBox = window.document.getElementById('identity-box');
        if (IdentityBox) {
            if (sss.sheetRegistered(identityBoxCssUri, sss.USER_SHEET)) {
                sss.unregisterSheet(identityBoxCssUri, sss.USER_SHEET);
            }
            sss.loadAndRegisterSheet(identityBoxCssUri, sss.USER_SHEET);
        }
        //end hide extended label for verified pages
        //colorize URL bar
        if (window.gBrowser) {
            window.FF7TweaksForScot = {}
            window.FF7TweaksForScot.gUrlBarColorize = function() { gUrlBarColorize.func(window) };
            window.FF7TweaksForScot.gUrlBarColorize();
            window.gBrowser.addEventListener('load', window.FF7TweaksForScot.gUrlBarColorize, true);
            window.gBrowser.addEventListener('pageshow', window.FF7TweaksForScot.gUrlBarColorize, true);
            window.gBrowser.tabContainer.addEventListener('TabSelect', window.FF7TweaksForScot.gUrlBarColorize, true);
        }
        //end - colorize URL bar
        //hide icons in bookmarks toolbar
        var PlacesToolbarItems = window.document.getElementById('PlacesToolbarItems');
        if (PlacesToolbarItems) {
            if (sss.sheetRegistered(bookmarksToolbarCssUri, sss.USER_SHEET)) {
                sss.unregisterSheet(bookmarksToolbarCssUri, sss.USER_SHEET);
            }
            sss.loadAndRegisterSheet(bookmarksToolbarCssUri, sss.USER_SHEET);
        }
        //end - hide icons in bookmarks toolbar
    },
    onUntrack: function (window) {
        //hide extended label when page is verified
        var IdentityBox = window.document.getElementById('identity-box');
        if (IdentityBox) {
            if (sss.sheetRegistered(identityBoxCssUri, sss.USER_SHEET)) {
                sss.unregisterSheet(identityBoxCssUri, sss.USER_SHEET);
            }
        }
        //end hide extended label for verified pages
        //colorize URL bar
        if (window.gBrowser) {
            window.gURLBar.style.backgroundColor = '';
            window.gBrowser.removeEventListener('load', window.FF7TweaksForScot.gUrlBarColorize, true);
            window.gBrowser.removeEventListener('pageshow', window.FF7TweaksForScot.gUrlBarColorize, true);
            window.gBrowser.tabContainer.removeEventListener('TabSelect', window.FF7TweaksForScot.gUrlBarColorize, true);
            delete window.FF7TweaksForScot;
        }
        //end - colorize URL bar
        //hide icons in bookmarks toolbar
        var PlacesToolbarItems = window.document.getElementById('PlacesToolbarItems');
        if (PlacesToolbarItems) {
            if (sss.sheetRegistered(bookmarksToolbarCssUri, sss.USER_SHEET)) {
                sss.unregisterSheet(bookmarksToolbarCssUri, sss.USER_SHEET);
            }
        }
        //end - hide icons in bookmarks toolbar
    }
});