How many countries have a purple colour in their flags?

In modern era, synthetic purple dyes became easier to obtain, and flags with purple colour began being used more commonly. Purple is one of the least used colours in vexillology and heraldry. Currently, the colour appears in only three national flags: that of Dominica, El Salvador, and Nicaragua, and one co-official national flag, the Wiphala (co-official national flag of Bolivia). However, it is also present in the flags of several administrative subdivisions around the world, as well as flags of political and ethnic groups and sexual minorities.

In the past, purple dye was very expensive to produce, with the first compound used as one, Tyrian purple, being made from the mucus of a family of sea snail found only in the eastern Mediterranean and off Mogador Island near Morocco.