Css3 uses @keyframes rule for the animation. Specify a CSS style inside the @keyframes rule ,the animation will gradually change from the current style to the new style.

<html>
<head>
<style type="text/css">
div
{
width:100px;
height:100px;
background:pink;
animation: one 10s;
-webkit-animation:one 10s; /* Safari and Chrome */
-moz-animation:one 10s; /* Firefox */
}

@keyframes one
{
0% {background:red;}
25% {background:gray;}
50% {background:orange;}
100% {background:white;}
}

@-moz-keyframes one /* For Mozilla Firefox */
{
0% {background:red;}
25% {background:gray;}
50% {background:orange;}
100% {background:white;}
}

@-webkit-keyframes one /* Safari and Google Chrome */
{
0% {background:red;}
25% {background:gray;}
50% {background:orange;}
100% {background:white;}
}
</style>
</head>
<body>

<p><b>Note:</b>My Name is Mahak Gupta </p>
<p><b>Note: Internet Explorer and Opera do not yet support the @keyframes or the animation property.
</b> </p>

<div></div>

</body>
</html>