First is that fiery color red, as in the idiom caught red-handed, which has a hyphen between red and handed. This means caught in the act of a crime, (1) as in “She was caught red-handed stealing $100.” As you might suspect, the use of the color red in the phrase originates from the color of blood. The phrase originally referred to blood on a murderer's hands but now extends to other crimes. (2) The noun red-hand has appeared in print in Scottish legal proceedings since 1432, (3) but red-handed was first printed in 1819, in Sir Walter Scott's novel Ivanhoe, which helped to popularize the phrase. (4)
Now we'll move from red to white, and the association of white with cowardice. If you say a man is white-livered or lily-livered, you are saying that he lacks courage, or that he is pale and without vitality. (5) It is easy to see why white is associated with being pale and unhealthy, but we need to dig a little deeper to discover what a pale liver has to do with being afraid.
It all goes back to the Ancient Greeks and Hippocrates, who proposed a theory called humorism. (6) This theory, which was believed until the 1800s, held that the body had four humors—black bile, yellow bile, phlegm, and blood—and that those humors needed to be kept in balance.
The humor that is relevant to the meaning of white-livered is yellow bile, supposedly made in the liver. Yellow bile, known as the choleric humor, is hot and dry, and it “provokes, excites and emboldens the passions.” (7) The idiom white-livered, therefore, stems from the thought that individuals without much yellow bile lacked a bold temperament and were therefore cowardly. (8)
3. Tickled Pink
Next on our list of colors is pink, and we're sticking with the medical theme. We hope you'll be tickled pink! The idiom tickled pink means delighted and first came into being in 1922. (9) The phrase uses the color pink because your complexion becomes flushed—and pinkish—when you feel the tickling sensation. (10) That's great if you enjoy tickling, but parents may want to think twice when tickling their children (or other people's kids). Laughing when being tickled is an automatic response (11) and the child may not actually enjoy the tickling. It can be difficult to say, “Stop!”
4. Yellow Journalism
Color number four—yellow—moves us to a different kind of sensation: sensational journalism, also known as yellow journalism. This style of reporting, which was at its height in the late 19th century, favors sensationalism over facts. (12) It all came about because of a rivalry between newspaper magnates Joseph Pulitzer, owner of the New York World, and William Randolph Hearst, owner of the Journal. The World published a popular cartoon that featured a character called the Yellow Kid, and this cartoon increased sales tremendously. (13) The Journal realized this and hired the artist away, causing a bidding war. Both papers also increased circulation by focusing their reporting on the Cuban struggle for independence, sometimes bending the truth. These days, our newspapers and Internet news sites are filled with banner headlines, colorful comics, and an abundance of illustrations, and we can thank the yellow journalists of the late 1890s for developing these now-commonplace techniques. (12)