Think of the Sen. Joseph McCarthy hearings into supposed Communist infiltration of Hollywood and the U.S. government in the early 1950s. See the paranoid Senator ranting in front of the wood-paneled hearing-room wall nearly covered with a Mercator Projection, a world map exaggerating the areal extent of the high-latitude lands of Communism represented by the Soviet Union, Eastern Europe, and China. (Do not blame Gerardus; he just wanted a straight line on his 16th-century map to coincide with straight-line sailing).
Next, select a color, Senator, to make the point that Communism was on a death march, about to take over the world: Use red--a deep, alarming, message-sending blood-red--to remind the American public of Stalin’s gulags and bloody purges, another being planned right up to his death. Then visually illustrate the second Red Scare in the U.S. by splashing the distressing blood-red on your blown-up map, as a signifier of your blown-up, seeing-Red rhetoric.
Success! You, sick Senator, have perfectly matched the message, the map, and the color.