I'm sorry, I know your link says it is easy to clear your browser cache, but I am stuck on instruction number one "Launch Mozilla Firefox and click the "Tools" button located on the main menu." I have no idea what launch means, or how to do it, and I can't find tools anywhere.
Restarting my pc did nothing either.
But fear not, I will live without coloured posts as long as you can reassure me that that is the only effect not being able to clear my browser cache. 