Change Background Color of CSS Element via Javascript

gistfile1.js

// Add hex colors you want to cycle through in this array
var colors = ['#E25243', '#00aeef', '#22d5e5', '#B8E986', '#F5A623', '#4A90E2', '#7F92A8', '#61C037', '#B370EF', '#ffdc29', '#FF6858'];
// Calculates the index of the array
// Math.random returns a decimal number between 0 and 1
// array.length returns number of items in array
var randomColor = Math.floor((Math.random()) * colors.length);var changeBackground = function() {
  // The element that you want to change needs to have a certain ID, which you can change here
  document.getElementById("changeColors").style.backgroundColor = colors[randomColor];
};
changeBackground();