under false colors

under false colors

Using or under the guise of false pretenses, so as to deceive someone or to hide one's true nature or intentions. (An allusion to the identifying flags of a ship, and so usually used in the phrase "sail under false colors.") Primarily heard in US. Tim thought he could just put on fancy clothes and rub elbows with the upper crust that Janet's family socialized with, but everyone at the party knew he was sailing under false colors. I don't want to be accused of flying under false colors, so let me say straight away that I'm being paid to give a review of this product today.
See also: color, false
Farlex Dictionary of Idioms.
See also:
  • false colors
  • sail under false colors, to
  • sail under false colours
  • sail under false colors
  • be sailing under false colors
  • be sailing under false colours
  • catfish
  • by false pretenses
  • by/on/under false pretences
  • under false pretenses
References in classic literature
Otherwise we shall be found sailing under false colors, and be inevitably cashiered at last by our own opinion, as well as that of mankind.
Walden & on the Duty of Civil Disobedience
"I have sailed under false colors." I felt now as if I must tell her that I had given her an invented name, on account of my fear that her aunt would have heard of me and would refuse to take me in.
Aspern Papers
Paul Mortenson (R-Mesa) told the Arizona Republic, "The message from Proposition 200 is, Do drugs, so what?" "What we have here," pronounced California Attorney General Dan Lundgren, "is a law flying under false colors."
Prescription: Drugs