CSS3使元素失色样式

-webkit-filter: grayscale(100%);/*chrome*/
-moz-filter: grayscale(100%);/*firefox*/
-ms-filter: grayscale(100%);/*IE*/
-o-filter: grayscale(100%);/*opera*/

//兼容IE9以下浏览器的写法
filter: grayscale(100%);
filter: progid:DXImageTransform.Microsoft.BasicImage(grayscale=1);
filter: gray;