Another good pictire here:
http://www.suzanneplunkett.com/images/Sulphur. jpg
And
CORBYLOON, I disagree with your first statement. Just because one small section of the community has decided to standardise (?-iZe) on what most consider to be the American spelling, does not suddenly make it the 'Correct Spelling'. Most people would take the 'Correct Spelling' of a word to be that which is found in a dictionary, but dictionaries are dynamic and change to reflect usage in the 'real world'.
Check the entry in Chambers:
http://www.chambersharrap.co.uk/chambers/featu res/chref/chref.py/main?title=21st&query=sulph ur
It still equates the ...F.. spelling with the US.
Look up pollution articles on any of the UK Newspaper websites or the BBC website and you will find references to 'sulphur emissions', 'sulphur dioxide' etc. Their readers would more than likely complain if they changed it.
So long as common usage of the word spells it as SULPHUR, then by definition, that will be the 'Correct Spelling'.
Only if you were writing a scientific paper for international readership would you be expected to conform with the SULFUR spelling.
Finally, If the Aberdeen Doric Preservtion Society decreed that the only 'correct' spelling henceforth would be LOUN, would you feel compelled to change your username?