> I always recommend to use only US English in your code. If you mix both British and American spellings, it will introduce some sort of confusion for later and might lead to interrogations for new developers joining the development of your software.

No it won't.

> Finally, I’ve noticed that it's easier to mispell words with the British spelling like typing “colur” instead of “colour”.

You misspelt "misspell". That significantly undermines your claim.