Negative connotation of red
Hair of Virgin Mary and the robes of Angels were depicted red in medieval paintings. The definitely positive connotation of the color red which originated with the neolithic hunter peoples and continued with the ancient Germans starts to change around 1500. The Germanic god Thor (other names include, Ása-Thór, Donar, Donner, Thór, Thunder, Tor) had red hair. [More about Thor from Ashliman at University of Pittsburg.] Red animals such as the robin, the fox and the squirel were Thor's sacred creatures. Beard and eyes of Wotan, the Germanic god of hunt, were fiery red too. Advent of Christianity diminished the power of these two Germanic gods. They were transformed into the devil with his red hair and red beard. Red haired women were reputed to be witches and whores and the poppy became the devil's flower. Sexuality which was also associated with red was demonized in Christianity. Mary's hair became blonde. Old sayings discriminated people with red hair or red beard: "Red hair, evil hair" and "Red beard - devil's way". Such prejudices still prevail in some rural areas of Europe.
The effect of the color red used to play an important role in politics. Red is the most frequently used color for national flags, mostly due to its excellent visibility. Red became the symbol of communism and socialism during the Russian Revolution in 1907. Red color had usually a positive connotation in cold countries like Russia throughout history. Red Army's alternative name was "Glorious Army" and Russian words for red (krassnyj) and beautiful (krassivyj) are very similiar. Western cultures frowned upon red color in its political sense. "Better dead than red" was popular in cold war days in the US. Black swastika of the National Socialists was painted on red background to suggest association with the working classes.