javascript - make HTML background always changing -

what mean 'always changing'? well, example, windows 8 installing screen, see text @ middle says:'you can new apps store', , background changing red orange yellow green cyan blue purple red. mean, how do html background javascript?

the simplest, effective , shortest amount of code using css , js

css:

#mydiv {     transition: background-color 2s; } 

then can set colors in array , call them when need, or ever often, or use below function generate random colors.

js:

function randomcolor() {     return '#'+ ('000000' + (math.random()*0xffffff<<0).tostring(16)).slice(-6) } 

here fiddle generates random colors every 2 seconds

https://jsfiddle.net/mlyyxmr1/2/

function randomcolor() {      return '#'+ ('000000' + (math.random()*0xffffff<<0).tostring(16)).slice(-6)  }    function setcolor(){      document.getelementbyid('mydiv').style.backgroundcolor = randomcolor();      settimeout(setcolor, 2000);  }  setcolor();

    #mydiv {          background-color: red;          transition: background-color 2s;      }

<div id='mydiv' style='width:200px;height:200px;'>        </div>