JSFiddle - React, Tailwind, and code Playground

HTML

<select id="settingBackground">
    <option name="default">Default</option>
    <option name="thankshaking">Background 2</option>
</select>

JavaScript

$(document).ready(function () {
    var selectedBG = localStorage.getItem("selectedBg");
    if (selectedBG) switchBg(selectedBG);
    $('#settingBackground').on('change', function () {
        localStorage.setItem("selectedBg", this.value);
        switchBg(this.value);
    });

    function switchBg(bg) {
        if (bg == "Default") {
            // Change background
            $('body').css("background", "#1e8cd4");
            $('body').css("color", "#fff");

        } else if (bg == "Background 2") {
            // Change background
            $('body').css("background", "url('http://i.imgur.com/cV7PKqh.jpg') no-repeat center center fixed");
            $('body').css("background-size", "cover");
            $('body').css("color", "#000");
        }
    }
});