change function not working

I have a SP app and one of functions is to change background color but the problem is that when I choose a color in drop down there's nothing happening.

<select id ="selectColor">
    <option>Red</option>
    <option>Blue</option>
</select>

var opt = $("#selectColor");

$(document).ready(function () {
    $("#selectColor").change(function () {
        if ($(this).text == "blue") {
            document.body.style.backgroundColor = "blue";
        }
    });
});