Color influences not only our emotions but also our memories. One study presented people with a list of emotionally charged words written in different colors. They were then asked to recall specific words. They were more likely to recall positive words written in green, leading researchers to theorize that green carries more positive emotional connotations. Thus, the color green might elicit an optimism bias when it comes to remembering information.Paper money is green in the United States, where the color is also associated with Irish-American culture, St. Patrick's Day, and good luck. Interestingly, one study found green may function as a good luck charm of sorts. Participants exposed to the color green experienced increased feelings of hope and decreased fear of failure.