sosidge.com

After 6 months of just “dealing with it” - I honestly thought Firefox did it deliberately to show up badly coded websites - I have finally found a solution.

It is in this thread - http://support.mozilla.com/tiki-view_forum_thread.php?comments_parentId=2926&forumId=1

Seems even the programmers behind Firefox don’t know the reason why - suggestions that it is the Intel onboard graphics at fault, or some deep-lying Windows colour setting - but the answer (for me at least) is this…

Go to Tools->Options->Content->Colours and tick “Use system colours”.

Sorts the problem and websites look as they should again!