<style>
/*变黑
img{ 
    -webkit-filter: grayscale(100%);
    -moz-filter: grayscale(100%);
    -ms-filter: grayscale(100%);
    -o-filter: grayscale(100%);	
	filter: grayscale(100%);
	filter: url(http://www.people.com.cn/img/2013people/gray.svg#grayscale);
	filter: gray;-webkit-filter: grayscale(1);
}
html {
	filter:progid:DXImageTransform.Microsoft.BasicImage(grayscale=1); 
	filter: gray;
	-webkit-filter: grayscale(1);
	}*/
</style>