When ever I type something, and use a word that can be spelled differently in English and American, Firefox always underlines my English spelling in red which means the spelling is incorrect when it is not incorrect , it is highlighting the fact that I should be using the American spelling. for example' When I type COLOUR which is the correct English spelling it is underlined in Red. If I type COLOR it is not underlined which it is stating is correct but this is the American spelling and I do not want to use American spellings. Therefore Firefox is using the American spellings and I DO NOT WANT my emails to companies to be typed in the American language, if I lived in America, so be it, but I live in the UK and want to use the English language thank you very much.