I would reinforce with your students just exactly what James has said,
that you are both correct AND that the science teacher is obviously
unaware of the difference. I, too, would inform the science guy that you
are not wrong, and that you do not appreciate him telling your
(collectively) students that you are giving them inaccurate
information. (Lucky for this guy he was not on the Millionaire TV show!
He would have lost when asked the colo question!)
I would make a point of telling your kids, this is just one more reason
why it is important to have art...to get the whole picture!
You can be gracious and thank them for sticking up for you as true
friends would, but let them know that his bullying manner is not going
to bother you. This is a wonderful opportunity to model behavior since
they are usually all subject to this type of behavior themselves. Good
luck. Let us know what happens.