通过css代码修改

    1. body {
    2.   /* IE */
    3.   filter: progid:DXImageTransform.Microsoft.BasicImage(grayscale=1);
    5.   /* Chrome, Safari */
    6.   -webkit-filter: grayscale(1);
    8.   /* Firefox */
    9.   filter: grayscale(1);
    10. }