JavaScript can be effectively used for changing the CSS of html page provided the whole CSS information is scripted in a .css file. We had the same scripted with the name as ThemeManager allowing to change the Color Scheme, font type, font size of the page. Actually I was bored for doing it for each and every style, I stopped after a few. But all that script can be viewed at ThemeManager Revealed . The ThemeManager is implemented at INDEX.