If you want change background color on button click, you should use JavaScript function and change a style in the HTML page.

function chBackcolor(color) {
   document.body.style.background = color;
}

It is a function in JavaScript for change color, and you will be call this function in your event, for example :

<input type="button" onclick="chBackcolor('red');">

I recommend to use jQuery for this.

If you want it only for some seconds, you can use setTimeout function:

window.setTimeout("chBackColor()",10000);

There is your code.

function myFunction() {
    var x = document.getElementById('box');
    if (x.style.backgroundColor === 'red') {
        x.style.backgroundColor = 'blue';
    } else {
        x.style.backgroundColor = 'red';
    }
}

#box{
background-color:red;
padding:1rem;
width : 50%;
height:150px;
margin:auto;
}

<div id="box" onclick="myFunction()">
</div>