> First, an OT question: Is there a Firefox extension that lets me
> *quickly* disable/enable page colors?

Use Opera! :-)  Shift+G toggles between the user and author modes.
Really handy.  I switch to the author mode only when page colors
matter.

No offense intended, but Opera is far more feature-rich, (yet the
features
are hidden until you explicitly unleash them), a bit lighter (less than
4 MB including flash and friends), a bit snappier (may depend on you
environment), etc.  What's the catch?  Nothing, except for the small
add
which is displayed if you don't pay (about US$40).

Sorry I couldn't resist to the chance of advocacy. :-)
I'm simpy a fan of Opera; I have nothing to do with the company,
by the way.

Cheers,
Ryo