2006, John Ayto, ed. Brewers Dictionary of phrase & Fable, 17th ed., ISBN 9780061121203,
In symbolism the colour yellow indicates jealousy, inconsistency, adultery, perfidy and cowardice. In France the doors of traitors used to be dubbed with yellow, and in some countries, the laws ordained that Jews must be clothed in yellow, because they betrayed Jesus, so that in medieval pictures, Judas Iscariot is arrayed in yellow. In Spain at an auto de fé, the victims wore yellow to denote heresy.
The denizens of the gossipy world of the pink press, purple prose and yellow tabloids are shivering over disputed photographs of Princess Caroline of Monaco.