// create a bookmark and use this code as the URL, you can now toggle the css on/off // thanks+credit: https://dev.to/gajus/my-favorite-css-hack-32g3 javascript: (function() { var domStyle = document.createElement("style"); domStyle.append( '* { color:#0f0!important;outline:solid #f00 1px!important; background-color: rgba(255,0,0,.2) !important; }\ * * { background-color: rgba(0,255,0,.2) !important; }\ * * * { background-color: rgba(0,0,255,.2) !important; }\ * * * * { background-color: rgba(255,0,255,.2) !important; }\ * * * * * { background-color: rgba(0,255,255,.2) !important; }\ * * * * * * { background-color: rgba(255,255,0,.2) !important; }\ * * * * * * * { background-color: rgba(255,0,0,.2) !important; }\ * * * * * * * * { background-color: rgba(0,255,0,.2) !important; }\ * * * * * * * * * { background-color: rgba(0,0,255,.2) !important; }' ); document.body.appendChild(domStyle); })();