html{
filter: grayscale(100%);
-webkit-filter: grayscale(100%);
-moz-filter: grayscale(100%);
-ms-filter: grayscale(100%);
-o-filter: grayscale(100%);
filter: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg'><filter id='grayscale'><fecolormatrix type='matrix' values='0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0.3333 0.3333 0.3333 0 0 0 0 0 1 0'></fecolormatrix></filter></svg>#grayscale");
filter:progid:DXImageTransform.Microsoft.BasicImage(grayscale=1);
-webkit-filter: grayscale(1);
}
body{
filter: grayscale(100%);/*火狐*/
-webkit-filter:grayscale(100%);/*chrome*/
filter:gray; /*IE7-9*/
}
<script type="text/javascript" src="./grayscale.js"></script>
<script type="text/javascript">
window.
grayscale(document.body);
}
</script>