The Instagram account @maps4u has uncovered four hidden sovereign flags in ours:
Sierra Leone: Green, white and blue.
South Africa's former state herald (yes, that's a legit and seemingly prestigious job) Frederick Brownell designed the flag after receiving a call in February 1994 tasking him with coming up with a national flag within a week. He told the BBC the idea of the new SA flag was along the lines of convergence and unification. "The convergence of the disparate groups within South African society, and their unification in one democratic state."
When it was introduced, the South African flag was the only country flag in the world that had six colours (within a seal or brocade). According to Brownell, the colours were just colours - and do not represent anything in particular.
These were some of the earlier designs, according to the book Flying With Pride: The Story of the South African Flag:
Also from Business Insider South Africa: