How to auto refresh these randomly generated colors

I've tried many solutions off my head like using setInterval in various ways but I can't seem to get it working.

Currently on every refresh, the patterns will all be random. The closest thing to what I wanted was that I made a setInterval and code but it only made 1 square continuously change its color. I deleted it by the way.

I just want after the page loads, it will continue to flip through random colors and not just be stuck on what was already generated.

var rndTile = Math.floor((Math.random() * 40) + 1);
var base = 2 / 2;
var colChoices = ["#81A594","#79BEDB","#6B78B4", "#593E1A", "#99CCCC"];
var fadeTime = Math.floor((Math.random * 6000));

Code: http://ift.tt/2aDds8u