As it is, there are only four primary passport colors across the globe, and countries have their own reasons for choosing one of them.
The Bright Side website found what the choices depend on and here they are:
Red passport is the most common one. The countries consist mostly of the ones with historical or current communist system. These countries include Slovenia, China, Serbia, Russia, Latvia, Romania, Poland, Georgia, and countries in the European Union (except Croatia) use shades of red too. Turkey, Macedonia, Albania – countries who have been interested in joining the EU – have also changed their passport colour to red. Bolivia, Colombia, Ecuador, and Peru – the Andean Community of Nations – also use burgundy, a shade of red.
After red, blue passports are the most common one. They are used by countries that symbolize “new world”. They consist of 15 Caribbean countries. Also in South American Countries, the blue passport symbolizes the connection with Mercosur, a trade union, which includes countries like Brazil, Argentina, and Paraguay (except for Venezuela, which has a connection with the trade union, but has a red passport). US Citizens use a blue passport, but it was only changed in 1976.
Countries like India, Australia also use Blue Passport.
According to Muslims, Prophet Muhammad’s favorite color was green since it symbolized nature and life. That’s why most Muslim countries share green passports. They include Morocco, Saudi Arabia, and Pakistan. Also, several West African countries like Burkina Faso, Nigeria, Niger, the Ivory Coast, Senegal and so on, use various shades of green as their passport. The colour for them is in relation to ECOWAS (Economic Community of West African States).
Black passports are used by very few countries. They symbolize some African countries like Botswana, Zambia, Burundi, Gabon, Angola, Chad, Congo, Malawi and few others. New Zealand also uses the black passport, but for them, it is mostly because their national colour is black.
The map below is painted according to the color of each country’s passport.