Which is British color or color?

The British spelling is colour with a U, while the American spelling is color without a U, and both are correct within their respective regional standards. In British English, which is used in the United Kingdom, Ireland, Australia, New Zealand, Canada, South Africa, and other Commonwealth countries, the standard and preferred spelling is colour, as listed in the Oxford English Dictionary. This spelling retains the French-influenced our ending that came into English after the Norman Conquest. In American English, used in the United States, the standard spelling is color, which was promoted by American lexicographer Noah Webster in the early 19th century as part of his effort to simplify and differentiate American spelling from British spelling, changing words like colour to color, flavour to flavor, honour to honor, and labour to labor. So if you are writing for a British audience or following British style guides, you should use colour. If you are writing for an American audience or following American style guides like AP or Chicago, you should use color. Both mean exactly the same thing and are pronounced identically, the difference is purely orthographic and regional.