White is a color, (more accurately it contains all the colors of the visible spectrum and is sometimes described as an achromatic color—black is the absence of color) that has high brightness but zero hue. The impression of white light can be created by mixing (via a process called "additive mixing") appropriate intensities of the primary color spectrum: red, green and blue, but it must be noted that the illumination provided by this technique has significant differences from that produced by incandescence (see below).
Color
Paint
In
painting, white can be created by
reflecting ambient light from a white
pigment, although the ambient light must be white light, or else the white pigment will appear the color of the light. White when mixed with black produces
gray. To art students, the use of white can present particular problems, and there is at least one training course specializing in the use of white in art.
There are various white pigments. Lead white, also known as flake white, is the traditional white pigment, but it is not much used now as it is toxic. Non-toxic alternatives are zinc white and titanium white. They are made from zinc oxide and titanium dioxide respectively.
White light
Until
Newton's work became accepted, most
scientists believed that white was the fundamental color of light; and that other colors were formed only by adding something to light. Newton demonstrated this was not true by passing white light through a prism, then directing the individual colored beams through another prism. If the colors were added by the prism, the second prism should have added further colors to the single-colored beam. Since the single-colored beam remained a single color, Newton concluded that the prism merely separated the colors already present in the light. White light is the effect of combining the visible colors of light in equal proportions.
In the science of lighting, there is a continuum of colors of light that can be called "white". One set of colors that deserve this description are the colors emitted, via the process called incandescence, by a black body at various relatively-high temperatures. For example, the color of a black body at a temperature of 2848 kelvins matches that produced by domestic incandescent light bulbs. It is said that "the color temperature of such a light bulb is 2848 K". The white light used in theatre illumination has a color temperature of about 3200 K. Daylight has a nominal color temperature of 5400 K (called equal energy white), but can vary from a cool red up to a bluish 25,000 K. Not all black body radiation can be considered white light: the background radiation of the universe, to name an extreme example, is only a few kelvins and is quite invisible.
Standard whites
Standard whites are often defined with reference to the
International Commission on Illumination's (CIE's) chromaticity diagram. These are the D series of standard illuminants. Illuminant D
65, originally corresponding to a color temperature of 6,500 K, is taken to represent standard daylight.
Computers
Computer displays often have a color temperature control, allowing the user to select the color temperature (usually from a small set of fixed values) of the light emitted when the computer produces the electrical signal corresponding to "white". The
RGB coordinates of white are 255 255 255.
Usage, symbolism, colloquial expressions
In general, since white is opposite of
black, it is often used with
positive connotation. Many negative expressions with "black" have an equivalent positive expression with "white". For example,
whitehat describes a person who is ethically opposed to the abuse of
computer systems, in contrast with
blackhat. White has also many other meanings:
- White is commonly the colour of snow and ice, though these often have a blue tint, even when not contaminated with other things that may change their color.
- The term white is often used in the West to denote "race" for so-called Caucasian people, i.e. people of European/West Asian descent with light skin color, whose skin color actually ranges from pink to pale brown, and overlaps with some people that might be classified as "Blacks". For more details, see Whites.
- White noise, in acoustics, is a sibilant sound that is often a nuisance, although it can also be deliberately created for test purposes.
- Whitewash, figuratively, means an attempt to obscure the truth by issuing a blanket of lies. See propaganda. Also, it refers to the action of burying or shoving someone's face into the snow, as a form of bullying, or harrassment(generally).
- Whiteout is a weather condition in which visibility is reduced and surface definition lost in snowy environments.
- In ancient China, white was the symbol of West and Metal, one of the main five colors.
- In English heraldry, white or silver (color) signified brightness, purity, virtue, and innocence. (The American Girls Handy Book, p. 369)
- White is the traditional color of bridal dress in both western (European) and Japanese weddings. In Western weddings, a white dress is thought to be symbolic of purity (the bride has not engaged in pre-marital sex). This is also said to be the symbolism of the veil. A white dress may simply indicate the bride's joy.
- A white paper can be an authoritative report on a major issue, as by a team of experts; a government report outlining policy; or a short treatise whose purpose is to educate (contrast position paper) industry customers. It is called white paper because it was originally bound in white.
- To "show the white feather" is to display cowardice. In cockfighting, a white feather in the tail is considered a mark of inferior breeding. In Victorian England a purported coward would be presented with a white feather.
- White has also become a prominent color depicting technology and the future in the 21st Century, most likely resulting from the heavy influence and increasingly widespread appeal of Apple Computer's products such as the Macintosh and the iPod.
- Butterflies of subfamily Pierinae of family Pieridae are commonly referred to as Whites, and the term forms part of many of the butterflies of this group, for example, Bath White.
See also
Shades of white
Wit (kleur) | ܚܘܪܐ | Bijela | Blanc | Bílá | Hvid | Weiß | Λευκό | Blanco (color) | Blanko | Blanc | Branco (cor) | Bianco | לבן | Wäiss | Balta | blabi | Abjad | Putih | Iztac | Wit | 白 | Hvit | Kvit | Blianc | Barwa biała | Branco | Белый цвет | White | Biela | Bela | Бела боја | Valkoinen | Vit | Trắng | Beyaz | 白色