Most people opt for blue when asked what their favorite color is (mine is black). Here are some thoughts about the color:
Why is the sky blue? Above the atmosphere, unfiltered white sunlight is actually a blend of colors from red to violet (ROYGBIV, if you remember your high school mnemonic). Our blue sky comes about because oxygen in the air interacts more with the violet end of the spectrum than with the red end. In the 1860s, England's Lord Rayleigh (John Strutt) figured out that when light encounters particles -- in this case, oxygen molecules -- many times smaller than the wavelength of that light, the light is refracted by an amount inversely proportional to the fourth power of the wavelength. So the refraction is five times greater for blue light (wavelength about 430 nanometers) than for red light (640 nm). The net effect is that the sun's blue light is selectively scattered all over the atmosphere, giving us a blue sky. The atmosphere scatters violet light even more, but our eyes are less sensitive to violet than to blue.
Why are Democrats blue? When it comes to assigning colors to political parties, the U.S. is the odd man out, since globally red is usually associated with left-leaning parties and vice versa. In the UK, for instance, the Conservative party is blue and Labour is red; same in Canada (Liberal/Conservative); New Zealand (Labour/National); France (Socialist/Union for a Popular Movement); Spain (Socialist Workers/People's); and Australia (Labor/Liberal) -- Aussie Liberals are right-leaning.
Colored electoral maps on TV during presidential election nights began in 1976 on NBC, with red Democrat and blue Republican states. (With our traditional three patriotic colors to choose from, and white the obvious "undecided," red and blue were the colors of choice -- they looked good on TV, too.) From 1976 until 2000, the colors alternated. Then came the recount debacle of 2000, when for 36 days the country was glued to maps on TV showing red states and blue states, especially the undecided state of Florida. As it happened, 2000 was a Democrat-blue year, and after that long and bitter fight the colors were set in stone. So whether you prefer roses to violets, you'd better get used to the idea of red/blue, elephants/donkeys, Republicans/Democrats.
Why is "sad" associated with blue? The connection goes back at least to 1385, when Chaucer wrote in The Complaint of Mars: "Wyth teres blewe, and with a wounded herte/Taketh your leave ..." In the 17th century came the phrase "blue devils," meaning sinister demons, which in turn led to "the blues" as a musical term, with flattened third and seventh notes creating a somewhat melancholy tone.
The original etymology may have something to do with rain, because in Greek mythology Zeus' tears made rain when he was sad. It all ultimately goes back to the Indo-European root bhel-, from which, in addition to blue, we get bleach, blemish, blanket and even flagrant and flame. I get blue in the face just thinking about it.
Barry Evans (email@example.com) sings the blues (and reds and greens) in Old Town Eureka, where his books are for sale at Eureka Books.