The English language is broad. Being the second-most spoken and most diverse language, it comes to no surprise that it differs from region to region. A person from Portland, Oregon will likely understand what a person from London is saying, but they might speak in a different accent and even a different dialect. It is important to know the nature of the English language as a writer.
One thing I had to be aware of when writing dialogue is the accent the speaking character will have. In The Tales of Draco, I use the typical American spelling (honor, color, scepter, etc.) in the narration because the main character speaks in that accent. But I use English spelling (honour, colour, sceptre, etc.) for characters with foreign accents, though that doesn’t necessarily mean the character’s accent is English. The spelling can also be changed in a way to put emphasis on how a character pronounces certain words. An example of the American/English spelling is used for Clipper. Clipper speaks with a Canadian accent, and words are spelled in the English style in Canada. Even though Clipper’s accent slightly differs from Jacob’s, it is still similar; so I still use American spelling for his dialogue. This contrasts with some of the dwarves and other characters where I use English spelling.
As I’ve mentioned before, when I use English spelling, it doesn’t always mean the accent is English. I use this spelling to indicate that the accent differs from Jacob and Clipper’s accents. You’ll see this American/English spelling more in future books in the series. When a character has a foreign accent, I use English spelling, even if the accent isn’t English. Sometimes the spelling will change in another way depending on the accent; it isn’t always English spelling.
I’m not saying the American/English technique is the correct way to add accent in dialogue. I’ve read plenty of books that use one type of spelling, even in dialogue. I just use the American/English technique in dialogue, depending on who is speaking. I only use American spelling in the narration.
If you ever decide to use the American/English technique, just remember to do it appropriately. Be aware of how you spell words in dialogue and most especially in the narration.