Compared with other colours, black carries many more negative connotations, such as death, misfortune and evil. The word “black” is often seen in expressions that describe something unpleasant or unfavourable. A blacklist, for example, consists of people deemed untrustworthy or unreliable. To talk about someone who is a disgrace to a group or a family, we can use the phrase black sheep: Peter is the black sheep of the family. He always gets himself in all kinds of troubles. Another example is black dog, which is used metaphorically to refer to melancholy or great sadness: After his wife passed away, his children have been the source of strength for him to keep the black dog at bay. This term was also used by famous English writers, including Samuel Johnson and Winston Churchill, to allude to their episodes of depression.

On the contrary, white is a symbol of hope, purity and kindness. For businesses that are struggling to stay afloat, their employees are likely to welcome the arrival of a white knight, which is to say an investor who comes to the rescue of a struggling company by either taking control of it or by providing new capital. To describe people who are of strong moral fibre and integrity, we can say that they are whiter than white: To gain support from donors and the public, charity workers are expected to be whiter than white. Interestingly, a lie, when associated with the word “white”, becomes somewhat less undesirable than it generally seems. A white lie is a benign untruth told to avoid hurting someone’s feelings. One example of a common white lie is: “Of course I remember you!”

If only everything in life were as simple as black and white.

Some phrases with the word “black” are neutral or positive in meaning. Black swan, for example, refers to an unexpected or rare event that has a huge consequential impact. Business owners will make every effort to capitalise on a black swan event to keep their company in the black, which of course means profitable. Before computers became common, accountants recorded income in black ink and expenses in red ink. No individual or business wants to be in the red, which means owing a debt or operating at a loss.

Similarly, expressions related to white might not necessarily be so complimentary. Unlike whiter than white, white as a sheet is not used to heap praise on someone who is decent and honest. Rather, it refers to a very pale face, usually the consequence of poor health or unpleasant feelings such as shock and fear. An elephant may look adorable, but the term white elephant is used to describe something that is expensive but utterly useless: The pavilion has become a $30 million steel and glass white elephant. Of late there have been views that it should be torn down.