Both "colour" and "color" are technically correct, but their usage depends entirely on which regional version of English you are following. "Colour" is the standard spelling in British English, as well as in most other English-speaking nations such as Canada, Australia, New Zealand, and India. The "u" was retained from the Old French origin of the word. Conversely, "color" is the exclusive spelling in American English. This shift was largely driven by Noah Webster in the late 18th century as he sought to simplify and "Americanize" the language in his influential dictionaries. In 2026, with the global dominance of American tech and media, "color" is frequently seen in digital coding and global marketing, but using the "u" remains a marker of high formal standards in the UK and Commonwealth countries. Choosing one over the other is less about "correctness" and more about maintaining consistency within your chosen dialect.