<script>
timerVar = setInterval(function(){change()},100);

function change(){
document.getElementById("durr").style.backgroundColor = getRandomColor();
}
function getRandomColor() {
    var letters = "0123456789ABCDEF".split("");
    var color = "#";
    for (var i = 0; i < 6; i++ ) {
        color += letters[Math.floor(Math.random() * 16)];
    }
    return color;
}
</script>