Ah, English; I love it. Well, not so much sometimes. Like just now.
I’m adapting a movie script into a novel and have caught myself several times now spelling a Canadian’s verbiage with British English in this American English novel. Somehow, I don’t think editing should go this way. Either the book is written in one or the other but not a blend of both. I guess.
Since my computer dictionary is set to American English, it does give me the annoying ‘red wiggles’ when I add those extra U’s to my otherwise good words such as colo(u)r and favo(u)r. But, hey, I still love Canada.