Any ideas as to how I might fix that?
You can't. The latest version of PPRuNe uses stylesheets to control ('nail') the colours. viz:
A:link, A:visited, A:active {COLOR: #000080;}
A:hover { COLOR: #000080;}
#ltlink A:link, #ltlink A:visited, #ltlink A:active {COLOR: #000080;
TEXT-DECORATION: none;}
#ltlink A:hover {COLOR: #000080;
TEXT-DECORATION: underline;}
Older versions of Netscape allowed you to disable stylesheets, I don't think IE ever did.