Many different colours appear in the world’s 254 national flags. The most popular colour combination used is red, white and blue. The USA, United Kingdom, France, Russia and 27 other nations fly this trio. Countries include red in their flags to represent everything from blood to bravery to revolution. Blue is used to signify, among other things, the sea, sky, truth and loyalty. White is a strong symbol of peace, purity and religion.
One colour is rarely found in national flags. Purple. Only two countries include it in their palette - Dominica and Nicaragua. In each of these flags you have to look carefully for the colour purple, it is used sparingly. There are two main reasons for this. For centuries, due to the complicated process of producing purple dye, it proved too expensive to incorporate into flag designs. Purple also has a time-honoured association with royalty, making it a risky colour for a nation to promote.