I’m an Australian freelancer, and I was working with an American Producer for an Australian market.

Me: You’ve misspelled colour. We use the British spelling, so here, “color” would be incorrect.

Client: I’ll think about it.

Me: Well it’s an Aussie client and an Aussie target market. It would be a bit embarrassing to not spell it correctly. 

Client: If it wasn’t for us saving your ass in World War II you would be Japanese!