select background color issue

HTML

<select id="mySelect">
</select>

JavaScript

var elementsCount = 300;

var select = document.getElementById("mySelect");

for (var i=0; i<elementsCount; ++i) {
    var option = document.createElement("option");
    option.text = "item " + i;
    option.value = i;
    option.style.color = ((i % 2 === 0) ? "red" : "yellow");
    option.style.backgroundColor = "black";
    select.appendChild(option);
}

//$('select option').css('background', 'black');
//$('select option').css('color', 'red');