The sibling comment is great, but I'd also like to add that it's important to keep in mind that English spelling was not particularly standardized until relativ

The sibling comment is great, but I'd also like to add that it's important to keep in mind that English spelling was not particularly standardized until relatively recently. People spelled words and even their own names however it seemed best to them at that particular moment in time. Variants like "color" and "colour" existed alongside each other peacefully for centuries and even in a single writer's mind. "Color" did not exit the British isles until quite late! For example, perusing through Google Books, you can find it in the 1829 edition of the London "Encyclopaedia", and in the 1844 edition of "The London Journal of Arts, Sciences, and Manufacture and Repertory of Patent Inventions."