A note from Wikipedia to make his harder:
Flags
Today only one nation in the world has purple or violet in its national flag; the Flag of Dominica, an island in the Caribbean, features a Sisserou parrot, a national symbol.
The lower band of the flag of the second Spanish republic (1931–39) was colored a tone of purple, to represent the common people as opposed to the red of the Spanish monarchy, unlike other nations of Europe where purple represented royalty and red represented the common people.[68]
In Japan, the prefecture of Tokyo's flag is purple, as is the flag of Ichikawa,
Porpora, or purpure, a shade of purple, was added late to the list of colors of European heraldry. A purple lion was the symbol of the old Spanish kingdom of León (910-1230), and it later appeared on the flag of Spain, when the Kingdom of Castile and Kingdom of León merged together.