What's the origin of the phrase "show true colours?"

I wonder if someone knows the actual origin and oldest printed record of the idiom "show true colours?" Other than this popular theory (seems not real to me):

This phrase dates back to the 1700s. It has a nautical origin and refers to the color of the flag which every ship is required to fly at sea. Pirates used to deceive other ships by sailing under false flags so that they would not excite suspicion. The other ships, thinking that the pirates were friendly, sailed close to them and fell under their grip. It was only after the attack that the pirates would show their 'true flag'.

References:

1. https://en.wiktionary.org/wiki/show_one%27s_true_colors
2. https://www.idioms.online/show-your-true-colors-to/
3. https://www.theidioms.com/show-true-colors/

Solution 1:

The OED's first citation is 1551, from Thomas Becon, A Fruitful Treatise of Fasting, which describes how Satan "setteth forth him selfe in his true colours". It's also in Shakespeare, Henry IV Pt 2 (1600) act 2 scene 2: "How might we see Falstaffe bestow himself to night in his true colours, and not our selues be seene?"

The sense of "colours" meaning livery (or some other show of allegiance) is older than Becon. But there are also a lot of metaphorical senses for "colour" that may be relevant.

The OED's definition of "colour" sense II.7.a is "Apparent or de facto legal authority or status, esp. as opposed to that actually granted or established. Frequently with negative connotations, suggesting that the authority is used as a pretext for illegal or corrupt behaviour (cf. sense 8). Chiefly in colour of authority, colour of law, colour of office. Now chiefly U.S." This goes back to 1325

Sense II.8 is "Outward appearance; show, aspect, or semblance of something, esp. as justifying a particular judgment, course of action, etc. Frequently, esp. in later use, with the implication that the appearance is false and used as a pretext. Now chiefly in legal contexts (see sense 7a)." This also goes back to 1325 with several late medieval/early modern uses.

There are various similar senses. None of this indicates the exact origin of the phrase, but you ask for the earliest example. It's clear "true colours" could mean some (often false or misleading) sign of authority or status, with various expressions about appearing, displaying, etc, these colours.

Reference: "colour | color, n.1". OED Online. March 2021. Oxford University Press. https://www-oed-com.nls.idm.oclc.org/view/Entry/36596?rskey=mb4ZyY&result=1&isAdvanced=true (accessed March 25, 2021).

Solution 2:

Here's an example of the phrase in actual use.

The Florida flew the British flag till she was fired at , when she hauled it down , and ( according to Captain Semmes's account ) hoisted Confederate colours . The unlucky Captain of the Oneida said in his report that his enemy “ had no flag to fight under . ” The discrepancy is immaterial , since she did not attempt to fight ; the only rule being that a ship may not fire without showing her true colours .

It is more to do with the rules of war between countries, rather than pirate ships. But it certainly comes from ships in war flying the flag of other countries, with a legal requirement that they lower false colours and show true colours before engaging in combat.