The term “blue” has come late in history since it was considered as a shade of white, black or green. It was the Egyptians who found a way to create blue paint. Blue was used during the antiquity era but less than red. The Greeks also considered the color of the sky and the color of the sea to be two different colors. During the Middle Ages, blue was used more, especially in painting with the Virgen Mary. It also became the official color of the French kings in the 12th century. Indeed, blue is still a color associated with France and its sports team today. At the beginning of the 18th century, people found other ways to produce blue dyes and nuances like cobalt and Prussian blue.
Blue is the second most used color on flags (red is first). Most of the countries of Oceania use this color on their flag too. It is often chosen because it represents water and the sea, which are important elements of coastal countries or islands. Otherwise, this color can also represent the sky, truth, and peace. On the Brazilian flag, the blue part represents the sky when the country became a republic. It is no accident that the United Nations and the European Union choose this color for their respective flags. In fact, blue, as it is the case with white, is related to peace.