pass with flying colours
idiom

- if you do something such as pass an examination with flying colours, you do it very successfully

(Cambridge Advanced Learner's Dictionary)

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The expression to "pass with flying colours" is one of the many phrases that have nautical or maritime origins. During the Age of Discovery (15th to 18th centuries) when the seas were full of sailing ships that carried out combat missions among other things, victorious ships would sail into port with flags on the ship's mast. These flags were and still are referred to as the "colours" and hanging them from the mast is referred to as "flying." Thus flying the colours became synonymous with success.

Other nautical phrases that have become part of everyday English include:

- batten down the hatches = to prepare for trouble. This idiom stems from the practice of securing a ship during heavy seas by battening (covering something with a protective sheet) the hatches (an opening in the ship's deck that leads to the lower levels).

- cut and run = to run away. This term is the shortened form of the earlier phrases "cut and run away" and "cut and run off." It has been suggested that it has a nautical derivation and that it refers to ships making a hasty departure by the cutting off the anchor rope and running before the wind.

- loose cannon = an unpredictable person. This expression derives from the idea of a cannon wildly rolling around the deck of a ship if it has not been secured with a rope.

- in the offing (to be imminent, to happen soon) In nautical terms, "offing" is the part of the sea that can be seen from land, excluding those parts that are near the shore. Someone who was watching out for a ship to arrive would first see it approaching when it was "in the offing" and expected to dock before the next tide.

- hand over fist (quickly and continuously) This phrase alludes to the action of pulling on a rope to bring it in, which of course is done "hand over fist."

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PRACTICE OWAD TODAY
Say something like:

"I'd like to say a big thanks to all of you for helping us PASS the audit WITH FLYING COLOURS!"