使用JS动态修改网页body的背景色

// ==UserScript==
// @name        ChangeBackgroundColor
// @namespace   tingl
// @include     *
// @version     1
// @grant       none
// ==/UserScript==

(function () {
  ‘use strict‘;
 
  var color = ‘#ececec‘;
  var style;
 
  function createStyle() {
    style = document.createElement(‘style‘);
    style.type = ‘text/css‘;
    style.innerHTML = ‘body {background-color: ‘ + color + ‘ !important;}‘;
  }
 
  function changeBackgroundColor() {
    if(!style.parentNode) document.head.appendChild(style);
  }
  
  createStyle();
  changeBackgroundColor();
  document.head.addEventListener("DOMNodeRemoved",changeBackgroundColor);
}) ()