Country flags
A flag is dyed cloth, so the authoritative specification is an ink or textile reference rather than a screen value, which is why almost no government publishes a hex. Of 250 countries surveyed, one had an official page carrying digital values. The rest are recorded from Wikipedia and labelled as such on every page, because the honest answer to "what is the official hex" is usually that there isn't one.
115 published, 13 of them with an official Pantone reference.