代码如下:

html{
-webkit-filter: grayscale(100%);
-moz-filter: grayscale(100%);
-ms-filter: grayscale(100%);
-o-filter: grayscale(100%);
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);
}