Use a regex to remove the font tags & their attributes from a page to undo highlighting applied using those self-same font tags

gistfile1.js

/*
* Clear the highlighting to allow the user to toggle
* between the original page & the highlighted page.
*/
function clearHighlighting()
{
alert("clearing hightlighting...");

if (!document.body || typeof(document.body.innerHTML) == "undefined") {
    if (warnOnFailure) {
      alert("Sorry, for some reason the text of this page is unavailable. Searching will not work.");
    }
    return false;
  }

var re = new RegExp('<'+'font'+'[^><]*>|<.'+'font'+'[^><]*>','g')
var bodyText = document.body.innerHTML;
bodyText = bodyText.replace(re, '');
document.body.innerHTML = bodyText;
return true;

}