Editing Pigment (section)

==Physical principles==
{{Main|Spectroscopy}}
[[File:Simple reflectance.svg|thumb|A wide variety of wavelengths (colors) encounter a pigment. This pigment absorbs red and green light, but reflects blue—giving the substance a blue-colored appearance.]]
Like all materials, the color of pigments arises because they absorb only certain wavelengths of [[light|visible light]]. The bonding properties of the material determine the wavelength and efficiency of light absorption.<ref>Thomas B. Brill, ''Light: Its Interaction with Art and Antiquities'', Springer 1980, p. 204</ref> Light of other wavelengths are reflected or scattered. The reflected light spectrum defines the [[color]] that we observe.

The appearance of pigments is sensitive to the source light. Sunlight has a high [[color temperature]] and a fairly uniform spectrum. Sunlight is considered a standard for white light. Artificial light sources are less uniform.

Color spaces used to represent colors numerically must specify their light source. [[Lab color space|Lab color]] measurements, unless otherwise noted, assume that the measurement was recorded under a D65 light source, or "Daylight 6500 K", which is roughly the [[color temperature]] of sunlight.
[[File:Complex reflectance.svg|thumb|400px|Sunlight encounters Rosco R80 "Primary Blue" pigment. The product of the source spectrum and the reflectance spectrum of the pigment results in the final spectrum, and the appearance of blue.]]

Other properties of a color, such as its saturation or lightness, may be determined by the other substances that accompany pigments. Binders and fillers can affect the color.