As the Mail says:
The future is gray for British English: How american spellings are taking over the world with flavor, center and defense becoming the norm
I take great delight in writing for Forbes using the English spellings. I discussed it with editors when I started and they were fine with it. And I have been amused at people shouting at me because I can’t spell labour, colour and the like.
I’ve gone further than this too. I used to take great pleasure in using the -ize endings, archaic English which American retained as English switched to -ise. Just because some pendant might come along and complain. But now that that joke is buried under writing for Americans I’ve switched to -ise.
I know, petty, petty stuff. But, you know, why not?