Using any theme other than the default means that it's just about impossible to post a message without logging in...
My web browser is configured to ignore colors specified by websites,
so the difference is less obvious. I still almost always remember
to log in, because if you're not logged in there's a login form on the
page, but I've been known to forget on occasion.
And no, I'm not going to subject myself to the arbitrary aesthetic
whims of every website I ever visit just so I'll notice more easily
if I'm not logged into Perlmonks. I haven't surfed the web with
site-specified colors enabled (well, not on anything resembling a
regular basis at any rate) since approximately 1998. Too many
webmasters have terrible tastes in colors.
Sanity? Oh, yeah, I've got all kinds of sanity. In fact, I've developed whole new kinds of sanity. You can just call me "Mister Sanity". Why, I've got so much sanity it's driving me crazy.