mark all border in page

markAllBackgrounds

//add javascript line into  your bookmark and click on a page
//known bug: if jquery is not loaded this will only work on the 2nd click

javascript: (function() {  if (!window.jQuery)  {      var script = document.createElement('script');  script.src="//ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js";  
document.body.appendChild(script);    }    if (window.markAllElementsBackground) {        $('*').each(function() {            $(this).css('background-color',$(this).data('save-background-color-data'))            });         window.markAllElementsBackground = false;     } else {        $('*').each(function() {            $(this).data('save-background-color-data', $(this).css('background-color')); var color = "#" + Math.floor(Math.random() * 0xFFFFFF).toString(16);$(this).css('background-color', color )});     window.markAllElementsBackground = true ;    }})();

markAllBorders

//add javascript line into  your bookmark and click on a page
//known bug: if jquery is not loaded this will only work on the 2nd click

javascript: (function() {  if (!window.jQuery)  {      var script = document.createElement('script');  script.src="//ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js";  
document.body.appendChild(script);    }    if (window.markAllElements) {        $('*').each(function() {            $(this).css('border',$(this).data('save-border-data'))            });         window.markAllElements = false;     } else {        $('*').each(function() {            $(this).data('save-border-data', $(this).css('border')); var color = "#" + Math.floor(Math.random() * 0xFFFFFF).toString(16);$(this).css('border','1px solid ' + color )});     window.markAllElements = true ;    }})();

an example of the result:
in one click you get
https://www.dropbox.com/s/ohzr4nvavupmgb8/mark%20elements%20on%20page.PNG?dl=0
and in 2nd click you can return to regular state