There are only four primary passport colors worldwide, and each country has its own reasons for choosing one of these colors for the cover.
Below is the reason to it:
This is the most common color. Passports with a red envelope are often chosen by countries with a historical or current communist system. Citizens of Slovenia, China, Serbia, Russia, Latvia, Romania, Poland and Georgia have red passports. With the exception of Croatia, the Member States of the European Union also use passports in Burgundy and other shades of red. Countries like Turkey, Macedonia and Albania that are interested in joining the EU changed the color of their passports to red a few years ago. The Andean Community of Nations – Bolivia, Colombia, Ecuador and Peru – also has burgundy-colored passports.
This is the next most common color. The blue cover symbolizes the “new world”. 15 Caribbean countries have blue passports. Within the block of South American countries, the blue passport holder symbolizes the connection to Mercosur – a union. This includes Brazil, Argentina and Paraguay. Venezuela is the exception here: it also belongs to the union, but its citizens have red passports. The passports of US citizens were only changed to blue in 1976.
Most Muslim countries have green passports. Examples are Morocco, Saudi Arabia and Pakistan. Green is considered the favorite color of the Prophet Muhammad and is a symbol of nature and life. Citizens of several West African countries – for example Burkina Faso, Nigeria, Niger, Ivory Coast and Senegal – also have travel documents in different shades of green. In their case, the color indicates that they belong to the ECOWAS (Economic Community of West African States).
The rarest passports are those with black lids. These are found among the citizens of some African countries – Botswana, Zambia, Burundi, Gabon, Angola, Chad, Congo, Malawi and others. New Zealanders also have black passport holders because black is the country’s national color.
Below is the representation of countries by their passport colors.