Thanks for the detail, that helps. Some sites paint colours straight onto the
elements, and nothing an ordinary stylesheet says can beat that. There's a
switch for it in All settings, under Stubborn sites. It has to ask for
permission on all sites, so it ships off. If that still doesn't take, open the
popup on that page and pick Generated under How this site is themed, or Invert
as a last resort (roughest looking, but it works anywhere). I'll go look at
forums.bsd.org myself and see which step it stalls on.