These are probably widely known and it's just me who did t know them or they're complete rubbish and I've been lied to but I was told today that the phrase passing with flying colours comes from ancient times when ships would go out to war or to discover new land and if they were successful they would return home with their flag (known as their colours) raised. Their colours were flying so they had passed the test with flying colours. Similarly showing your true colours comes from the fact that ships would often fly false flags to disguise who they were and so when they flew the correct flag and could bee seen accurately they were literally showing their true colours. Like I said they're either boring, well known or ********. Sums up my posting history on here tbh
