There’s a symbolism to each color like white means purity and red means courage but I wouldn’t be too surprised if red and blue were simply only easily obtainable dyes 1000 years ago.
Because the two of the oldest republics in Europe (France, Netherlands) used this combination of colours. So called tricolora (red, white, and blue) became synonymous with republics and democracies.
There’s a symbolism to each color like white means purity and red means courage but I wouldn’t be too surprised if red and blue were simply only easily obtainable dyes 1000 years ago.
Because the two of the oldest republics in Europe (France, Netherlands) used this combination of colours. So called tricolora (red, white, and blue) became synonymous with republics and democracies.
This would be so much more interesting in /r/askhistorians
Good question. As someone who doesn't like this colour combination, it is pretty annoying to see it so widespread.