This is a simple JavaScript example to fade out a background color using function and array...

Click to fade out   Green

 
function fade(id) {
    var dom = document.getElementById(id),
        level = 1;
    function step () {
        var h = level.toString(16);
        dom.style.backgroundColor = '#FF'+h + h + h + h;
        if (level < 15) {
            level += 1;
            setTimeout(step, 100);
        }
    }
    setTimeout(step, 100);
}
function green(id){
   var dom = document.getElementById(id);
   dom.style.backgroundColor = '#009966';
}