<style>
html { 
	-webkit-filter: grayscale(100%);
	-moz-filter: grayscale(100%); 
	-ms-filter: grayscale(100%); 
	-o-filter: grayscale(100%); 
	filter: progid:DXImageTransform.Microsoft.BasicImage(grayscale=1);  
	_filter: none; 
}
</style>