The designs on many world flags have historical significance. Vexillology, or the study of flags speaks to the diverse experiences of different cultures around the world.
For example, the South African flag reflects the country’s British, Dutch and African history. It features half a union jack for the British, the red and blue horizontal colors which remind one of the Dutch flag and green, yellow and black, the colors of the African National Congress.
For more fascinating examples of how flags display culture, check out the article below. http://www.news.com.au/technology/innovation/design/australia-china-india-germany-secrets-hidden-in-world-flags/news-story/5370a38ac48b11193490c88c3f2ad951