Edit in JSFiddle

	.rotate {
		background-color: red;
		width: 200px;
		height: 200px;
		transition: transform .8s;
 		-webkit-transition: -webkit-transform .8s ease-in-out;
    	-ms-transition: -ms-transform .8s ease-in-out; 
		
	}

	.rotate:hover {
		transform:rotate(90deg);
		-ms-transform:rotate(360deg);
		-webkit-transform:rotate(360deg);
		-webkit-filter: grayscale(100%);
	}