Стилизация select на javascript?

function tamingselect() {
    if (!document.getElementById && !document.createTextNode) { return; }

    // Classes for the link and the visible dropdown
    var ts_selectclass = 'turnintodropdown_demo2';  // class to identify selects
    var ts_listclass = 'turnintoselect_demo2';      // class to identify ULs
    var ts_boxclass = 'dropcontainer_demo2';        // parent element
    var ts_triggeron = 'activetrigger_demo2';       // class for the active trigger link
    var ts_triggeroff = 'trigger_demo2';            // class for the inactive trigger link
    var ts_dropdownclosed = 'dropdownhidden_demo2'; // closed dropdown
    var ts_dropdownopen = 'dropdownvisible_demo2';  // open dropdown
    /*
        Turn all selects into DOM dropdowns
    */
    var count = 0;
    var toreplace = new Array();
    var sels = document.getElementsByTagName('select');
    for (var i = 0; i < sels.length; i++) {
        if (ts_check(sels[i], ts_selectclass)) {
            var hiddenfield = document.createElement('input');
            hiddenfield.name = sels[i].name;
            hiddenfield.type = 'hidden';
            hiddenfield.id = sels[i].id;
            hiddenfield.value = sels[i].options[0].value;
            sels[i].parentNode.insertBefore(hiddenfield, sels[i])
            var trigger = document.createElement('a');
            ts_addclass(trigger, ts_triggeroff);
            trigger.href = '#';
            trigger.onclick = function () {
                ts_swapclass(this, ts_triggeroff, ts_triggeron)
                ts_swapclass(this.parentNode.getElementsByTagName('ul')[0], ts_dropdownclosed, ts_dropdownopen);
                return false;
            }
            trigger.appendChild(document.createTextNode(sels[i].options[0].text));
            sels[i].parentNode.insertBefore(trigger, sels[i]);
            var replaceUL = document.createElement('ul');
            for (var j = 0; j < sels[i].getElementsByTagName('option').length; j++) {
                var newli = document.createElement('li');
                var newa = document.createElement('a');
                var newspan = document.createElement('span');
                newli.v = sels[i].getElementsByTagName('option')[j].value;
                newli.elm = hiddenfield;
                newli.istrigger = trigger;
                newa.href = '#';
                newa.appendChild(document.createTextNode(
                    sels[i].getElementsByTagName('option')[j].text));
                newli.onclick = function () {
                    this.elm.value = this.v;
                    ts_swapclass(this.istrigger, ts_triggeron, ts_triggeroff);
                    ts_swapclass(this.parentNode, ts_dropdownopen, ts_dropdownclosed)
                    this.istrigger.firstChild.nodeValue = this.firstChild.firstChild.nodeValue;
                    return false;
                }
                newli.appendChild(newa);
                replaceUL.appendChild(newli);
            }
            ts_addclass(replaceUL, ts_dropdownclosed);
            var div = document.createElement('div');
            div.appendChild(replaceUL);
            ts_addclass(div, ts_boxclass);
            sels[i].parentNode.insertBefore(div, sels[i])
            toreplace[count] = sels[i];
            count++;
        }
    }

    /*
        Turn all ULs with the class defined above into dropdown navigations
    */

    var uls = document.getElementsByTagName('ul');
    for (var i = 0; i < uls.length; i++) {
        if (ts_check(uls[i], ts_listclass)) {
            var newform = document.createElement('form');
            var newselect = document.createElement('select');
            for (j = 0; j < uls[i].getElementsByTagName('a').length; j++) {
                var newopt = document.createElement('option');
                newopt.value = uls[i].getElementsByTagName('a')[j].href;
                newopt.appendChild(document.createTextNode(uls[i].getElementsByTagName('a')[j].innerHTML));
                newselect.appendChild(newopt);
            }
            newselect.onchange = function () {
                window.location = this.options[this.selectedIndex].value;
            }
            newform.appendChild(newselect);
            uls[i].parentNode.insertBefore(newform, uls[i]);
            toreplace[count] = uls[i];
            count++;
        }
    }
    for (i = 0; i < count; i++) {
        toreplace[i].parentNode.removeChild(toreplace[i]);
    }
    function ts_check(o, c) {
        return new RegExp('\\b' + c + '\\b').test(o.className);
    }
    function ts_swapclass(o, c1, c2) {
        var cn = o.className
        o.className = !ts_check(o, c1) ? cn.replace(c2, c1) : cn.replace(c1, c2);
    }
    function ts_addclass(o, c) {
        if (!ts_check(o, c)) { o.className += o.className == '' ? c : ' ' + c; }
    }
}

window.onload = function () {
    tamingselect();
    // add more functions if necessary
}

 

.dropcontainer_demo2 {
  position: relative;
  font-size: 16px;
  color: #777;
}

.trigger_demo2 {
  padding: 12px 12px 12px 16px;
  border: 1px solid #ebe6e1;
  cursor: pointer;
  width: 100%;
  border-radius: 4px;
  display: block;
  background-color: rgba(168, 149, 131, 0.04);
  transition: all 0.5s ease;
}

.trigger_demo2:hover {
  color: #777;
}

.activetrigger_demo2 {
  padding: 12px 12px 12px 16px;
  cursor: pointer;
  width: 100%;
  border-radius: 4px;
  display: block;
  background-color: rgba(168, 149, 131, 0.1);
  border: 1px solid #a89583;
  transition: all 0.5s ease;
}

.activetrigger_demo2:hover {
  color: #777;
}

.activetrigger_demo2:active {
  color: #777;
}

.dropcontainer_demo2 ul {
  z-index: 100;
  position: absolute;
  top: 8px;
  min-width: 100%;
  left: 0;
  max-height: 400px;
  background-color: #fff;
  border-radius: 4px;
  box-shadow: 0 2px 8px rgb(31 27 22 / 8%);
  padding: 8px;
}

.dropcontainer_demo2 ul li {
  padding: 8px 40px 8px 8px;
}

.dropcontainer_demo2 ul li a span {
  margin-left: 16px;
  font-size: 14px;
  line-height: math.div(20, 14);
  color: rgba(129, 109, 94, 0.6);
}

.dropcontainer_demo2 ul li:first-child {
  display: none;
}

.dropdownhidden_demo2 {
  display: none;
}

.dropdownvisible_demo2 {
  height: auto;
}

.dropdownvisible_demo2 {
  max-height: 400px;
  overflow-y: scroll;
}

<select class="turnintodropdown_demo2">
  <option>Выберите размер</option>
  <option>S <span>Мало</span></option>
  <option>M <span>Мало</span></option>
  <option>L</option>
  <option>XL</option>
  <option>XXL <span>Мало</span></option>
</select>