How much do you know about BLUE?

BLUE, a primary color but the rarest in nature, was considered a form of black until about 5,000 B.C/ In many languages, there is no word for blue; a term referring to both blue and green often suffices for either color./ Blue can connote winning (blue ribbon), loyalty (true blue), sadness (the blues), the ocean and the sky, communication (U.S postal services, phone booths), the Hindu god Krishna, a toothpaste brushes, the Union army in the American Civil War, or the Democratic party. /Writing in 1978, leading color authority Faber Birren stated that people whose favorite color is blue are dovoted and introspective, that they "make able executives and golfers, and they usually dwell in neighborhoods where other blue lovers are to be found"