Idiom Origin: Show One's True Colours
To ‘show one’s true colours’ has long been a phrase meaning the revealing of one’s true character, be it good or bad. The phrase as we know it was first cited in 1551 by Thomas Becon in A Fruitful Freatise of Fasting where, speaking of Satan, he wrote that he ‘setteth forth him selfe in his true colours.’ Shakespeare also used this figurative phrase in Henry IV Pt II Act III scene II with the line ‘how might we see Falstaffe besstow himself tonight in his true colours.’ However, though often used figuratively, the idiom has a very literal origin.
It’s nautical in origin and harkens to the era of tallships as a ship’s flags were commonly referred to as its ‘colours’ and was how ships would identify themselves to one another. Sometimes a ship would lower its colours to keep it hidden or even fly under a false flag to gain an advantage or cause confusion during times of warfare. However, the rules of warfare required that a ship must show its actual flag before firing and thus the counterfeit flag would be switched and the ship’s true colours raised as they showed to which nation they held their true alliegance. This was also a tactic used by pirates allowing them to get in close to their targets before they hoisted their own colours to strike fear and reveal their true intentions. Thusly, their ‘true colours’ were shown and a new idiom was born.
The phrases ‘under false colours’ and ‘false flags’ were also derived from the same origin.
Fascinating!