Spelling is tricky all on it’s own. When you throw in different languages and cultures it gets down right complicated.
First, consider English and American spelling. Then throw in Canadian spelling, which is some combination of the two. Same for other countries in the commonwealth.
Have you seen words spelt with an s instead of a z? You would if you were English or from South Africa. Do you see words with a u in them or without a u in them? You would see them with added u if you were English or Canadian.
Which is right? How do you know which spelling to use? Will people think you just don’t know how to spell? Possibly.
But the world is a big place, if you were writing locally you would spell for your readers. But, when you are writing on the Internet, your readers come from all over the world. Which spelling should you choose?
First, talk to your publisher or editor. Find out what they use for a standard. They call those style guides. It’s a good idea for publications to have one. Not just for different spelling issues. If you’re more or less on your own as for style, go with what comes naturally to you. It’s hard to remember to spell a different way. Likely you’ll miss a few anyway. You may hear from the odd reader who thinks you don’t know how to spell. But, that just gives you something to chat about in your reply to them.
Is spelling an art or a science? I think I’ll leave that as thought fodder for you.