greyscale.scss

/**
 * Cross-browser image desaturation filter
 *
 * 1. Chrome 19+, Safari 6+, Safari 6+ iOS
 * 2. Firefox 10+, Firefox on Android
 * 3. IE6-9
 */
%greyscale {
    -webkit-filter: grayscale(100%);  /* [1] */
            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\'/></filter></svg>#grayscale");  /* [2] */
            filter: gray;  /* [3] */
}