Young Blonde Girl Shows Off On The White Bed

Since the impression of white is obtained by three summations of light intensity across the visible spectrum, the number of combinations of light wavelengths that produce the sensation of white is practically infinite. There are a number of different white light sources such as the midday sun, incandescent lamps, fluorescent lamps and white LEDs; due to the phenomenon of metamerism, such sources can appear similar whilst having quite different spectra. The impression of white light can also be created by mixing appropriate intensities of the primary colors of light, red, green and blue (RGB), a process called additive mixing, as seen in many display technologies.
• Color temperature
The best known way to generate white light is by the process called incandescence, or black body radiation where bodies of atoms with a certain temperature emit a certain type of radiation. For example, the color of a black body at a temperature of 2,848 kelvins. This is closely matched by incandescent light bulbs. The correlated color temperature of such a light bulb is 2,848 K. Daylight can vary from a cool red up to a bluish 5,600 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 hot, and is not visible.
In astronomy the stellar class of stars are determined by the color temperature. For instance are white dwarfs small dense stars thought to be the final evolutionary state.