What is the color blue?
A: Blue is one of the three primary colors in the RYB color model
(traditional color theory), as well as in the RGB (additive) color model.
It lies between violet and what, on the spectrum of
visible light?
A: Cyan.
The eye perceives blue when observing light with a
dominant wavelength of what?
A: Between approximately 450 and 495 nanometers.
Most blues contain a slight mixture of other colors;
azure contains some what?
A: Green, while ultramarine contains some violet.
Why does the clear daytime sky and the deep sea appear
blue?
A: Because of an optical effect known as Rayleigh scattering.
An optical effect called Tyndall effect explains what?
A: Blue eyes.
Distant objects appear bluer because of another optical
effect called what?
A: Aerial perspective.
Blue has been an important color in what since ancient
times?
A: Art and decoration.
The semi-precious stone lapis lazuli was used in
ancient Egypt for what?
A: jewelry and ornament.
Later, in the Renaissance, to make what pigment, the
most expensive of all pigments?
A: The pigment ultramarine.
In the eighth century Chinese artists used what to color
fine blue and white porcelain?
A: Cobalt blue.
In the Middle Ages, European artists used it in the
windows of what?
A: Cathedrals.
Europeans wore clothing colored with the
vegetable dye woad until it was replaced by what?
A: The finer indigo from America.
In the 19th century, synthetic blue dyes and pigments
gradually replaced what?
A: Organic dyes and mineral pigments.
Dark blue became a common color for what uniforms?
A: Military uniforms and later, in the late 20th century, for business
suits.
Because blue has commonly been associated with harmony,
it was chosen as the color of the flags of what?
A: The United Nations and the European Union.
Surveys in the US and Europe show that blue is the
color most commonly associated with what?
A: Harmony, faithfulness, confidence, distance, infinity, the imagination,
cold, and occasionally with sadness.
In US and European public opinion polls it is the most
popular color, chosen by who?
A: Almost half of both men and women as their favorite color.
The same surveys also showed that blue was the color
most associated with what?
A: The masculine, just ahead of black.
