[Pernickety]

I know this is an old discussion but thought I'd add something that hasn't been mentioned.

Students/schools should be allowed to choose one way and STICK WITH IT.

I actually came across the opposite to the original poster when teaching in Japan. Teachers there seem to prefer the American way and I had to adapt to this. I wanted to correct 'color' but held myself back! But the message we gave to students was that they could choose British spelling/words but not to mix and match.