It turns out that the colour of a passport can actually help to identify sovereign nations.
According to Business Insider, countries which are part of the same political or economic organisation usually have the same passport colour.
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The USA, Canada and Mexico are all NAFTA (North American Free Trade Agreement) nations and all have blue passports.
Globally, passports come in varying shades of red, blue, green and black.
Most EU passports are burgundy, but so are the passports of Turkey, Macedonia and Albania.
Turkey previously had green passports, like most middle-eastern countries, but they later switched to burgundy.
It's not just the colour of passports that has changed over time; the pages inside have seen development too.
Countries like the UK, US and China all feature images on their passport pages that are only visible under a UV light.
The Passport Index website has a comprehensive list of passports around the world and also ranks their visa free score, individual rank and global rank.
The website also outlines which countries you need a visa to visit dependent on your passport.
Similarly, it explains whether you require a visa prior to arrival or whether your visa will be granted on arrival.