Not that I hadn't heard that phrase before, only that I'd never wondered exactly what it meant. I pictured either a rainbow on a breeze or else maybe flags.
- My guess about the flags is the correct one.
- "Colors" is a sort of heraldry-slang way to refer to the flag of one's nation.
- Thus, to fly one's colors means you're going to raise and unfurl your flag.
- The flying part of the phrase comes from ships' flags. In the 1700s, it became the practice for ships that were victorious in a sea battle to return to port with the flags of their home country flying from every mast of the ship; that is, triumphantly.
This replica of an 18th century gun ship is not flying any flags. In sailing language this means, "This ship has surrendered," or "This ship belongs to no country." It's not a good sign. Most ships fly at least one flag to tell other ships who they are. Since I saw a lot of images of ships with no flags, I bet whoever is in charge of this ship doesn't realize they're sending out bad signals by not flying any flag.
(Photo from the Port of Redwood City)
This is a 17th century Dutch ship, as depicted by a Japanese artist from that time. Those are national and royal flags and banners of the Netherlands. Flying all those flags in front of people from another country is like using allcaps in flag language to shout: HA HA SUCKERS, THIS IS OUR SHIP, LA LA LA LA! Flying all of your flags as you sail into your home port is like shouting, WOO-HOO, WE WON! BREAK OUT THE CASKS OF WINE!
(Image from Japan Probe)
- Taken all together, "to come through it with flying colors" means that you'll be victorious in your pursuit. You may have to work hard (battle) for that victory but in the end it will be a complete (flags from all masts) success.
- Or rather than having to work at it, you might sail through it. Har har.
You might also be interested in the phrase three sheets to the wind.
The Phrase Finder, Flying colors; false colors
Pride UnLimited, Idioms & Axioms
die.net, online dictionary, to come off with flying colors
Audio English.net, Flying Colors
Dictionary of Vexillology, Colours (or Colors)
Britannica, flag, form and functions