There are only four possible colors for passports: red, blue, green and black, but some nuances in the shades are visible. Nations themselves decide on the color of their passport cover based on their political and cultural preferences. Thus, the shade chosen reflects a cultural, religious, political or simply the origin of a continent. It is one of the symbols of government.
The color red is often chosen by countries with a communist past (the so-called “red” countries), such as Russia, Serbia, Romania and Slovenia or countries still communist such as China.
Red is also associated with Nordic countries such as Denmark, Sweden, Finland and Norway because of an association with the Vikings.
Otherwise, all passports of the European Union countries are in burgundy, a color validated by a resolution signed by the member countries in 1981. By the way, Turkey has decided to change the color of its passport from green to maroon in the hope of getting closer to the European Union.
In general, this color is very often associated with the countries of the Americas: all the Caribbean countries, those who are members of the Caribbean Community (CARICOM), wear blue. It is also the case for the countries of South America (Brazil, Argentina, Paraguay and Uruguay).
In the United States, the passport became blue in 1976 to celebrate the bicentennial of independence and to refer to the blue of the American flag.
Canada also owns the blue passport, to show its belonging to the American continent.
Green is the color generally chosen by countries where the Muslim religion is predominant: Morocco, Pakistan, Saudi Arabia, etc. This would come from the fact that green would be the favorite color of the prophet Mohammed. Thus, green is present in most Islamic countries: Iran, Mauritania, Afghanistan.
From another point of view, some African countries have opted for this shade to signify their membership in the Economic Community of West African States (ECOWAS). This is the case of Burkina Faso, Côte d’Ivoire, Niger, Nigeria and Senegal.
Black passports are the least common. They are used by countries for which the color black refers to the black continent; Africa. This is the choice of Chad, Zambia, Botswana, Burundi, etc.
Black is also chosen by New Zealand for cultural reasons, its famous All Blacks!
Black passports are sometimes issued to diplomatic personnel because they look more official and are less likely to get dirty.
Finally, some passports are exempt from the rule and have different colors. These non-traditional colors are used mostly for temporary passports, issued exclusively for urgent travel (examples: white in Canada, beige in the United Kingdom).