He'll only get a green cast if he mixes lighting types. If *everything* in the room uses the same colour fluorescents, then the camera's
manual white balance feature will give colour correct images.
But usually there is a mix of lighting.. in which case beware the
green cast.
And WTF is with
the BBSFirefox trying to tell me I'm spelling
colour and
fluorescent incorrectly???
This is an international forum with an international mix of people, and it really shouldn't be inflicting one country's poor speling on the rest of us! 
EDIT: fixed by installing a British English dictionary extension.