Chromatic color

Table 11. Chemical Composition and ASTM Specifications for Chromate Color Pigments ...

Achromatic colors are white, black, and gray. Black and gray differ from white only in their relative reflection of incident light. The purples are nonspectral chromatic colors. All other colors are chromatic for example, brown is a yellow of low lightness and low saturation. It has a dominant wavelength in the yellow or orange range. 

Color The color of the film can affect the consumer acceptance of coated produce (60). Five different color systems XYZ, Yxy, L a b, L C H° and Hunter Lab are used to express absolute chromaticity. Color system XYZ is measured as tristimulus values of color and forms the basis for most calculations. In the color system Yxy, Y is a lightness factor expressed as a percentage based on a perfect reflection of 100%. x and y are chromaticity coordinates defined by the following equations ... 

Immediately flush with plenty of water for at least 15 minutes, persistent dermatitis should be referred to a physician. Wash contaminated skin or clothing until chromate color disappears. 

USE In tanning industry dyeing chromate colors on wool. 

Pigment red 38 Zinc chromate colorant, food-grade polymers Cobalt aluminum oxide Ferric oxide Iron oxide yellow monohydrate colorant, food-marking inks Annatto (Bixa orellana) Annatto (Bixa orellana) extract... 

Pigment red 122 Strontium chromate colorant, R PVC Solvent red 179 colorant, resins... 

Here, of particular importance is their very high opacity coupled with highly chromatic colors, which in turn contribute towards even further opacity by enabling combinations with opacifying but less chromatic inorganic pigments. THI pigments are thus preferred for mass-tone applications in most areas. 

Given an initial pltysical match, a difference in color can be introduced by either of two procedures, which are often carried out in combination. In the first instance, the radiance of one part of a homogeneous field is altered without any change in its relative spectral distribution. This produces an achromatic color difference. In the second case, the relative spectral distribution of one field is changed such that, for all possible relative radiances of the two fields, no match is possible. This is called a chromatic color difference. 

The values X, T, and Z are called relative tristimulus values these are equal for any light having an equal-radiance spectrum. Tristimulus values permit the specification of color in terms of three variables that are related to cone sensitivities rather than by continuous spectral radiance distributions, which do not. Like R,G, and B, the tristimulus values represent the coordinates of a three-dimensional vector whose angle specifies chromatic color and whose length characterizes the amount of that color. 

For a surface that does not fluoresce, its spectral reflectance characteristics can modify the quantity and geometry of incident monochromatic light, but not its wavelength. Viewed under separate monochromatic light sources of the same wavelength, any two surfaces with arbitrarily chosen spectral distributions can be made to match, both physically and visually, by adjusting the relative radiances of incident lights. Therefore, no chromatic color differences can exist under monochromatic illumination. 

The amount of visible light emitted by a source is measured in lumens, determined by integrating its radiant power output S(X) with the spectral luminous efiiciency function F(X). The latter, which is proportional to y(X), peaks at 555 nm. Therefore, the theoretically most efii-cient light source would be monochromatic at this wavelength, with the associated inability to render chromatic color differences. Efiicacy does not include power lost in the conversion fi om electrical input to radiant output, which may vary independently of the efiicacy of the light finally produced. 

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