I'm running a game where two of the characters (and not the players) are colourblind, and I was wondering if I (or they, I trust them to follow through) could somehow switch their views to grayscale. I tried the javascript bookmarklet javascript:(function(){var%20e=document.body;e.style.filter="progid:DXImageTransform.Microsoft.BasicImage(grayscale=1)",e.style.filter||(e.style["-webkit-filter"]="grayscale(1)",e.style.filter="grayscale(1)")}()), which does it on most websites but doesn't seem to work with the Roll20 app (I guess because it uses its own rendering tricks). Anyway, I was wondering if anyone had any suggestions. Thanks.