color match under a given spectrum of light. A spectral color match attempts to give two colors the same spectral reflectance characteristic, making them a good metameric match with a low degree of metamerism, and thereby reducing the sensitivity of the resulting color match to changes in illuminant, or differences between observers. One way to circumvent metamerism in paints is by using exactly the same pigment and base color compositions in the reproductions as the ones which were used in the original. When the composition of pigment and base color is unknown, metamerism can be avoided only with the use of colorimetric devices. Printing industry The printing industry is also affected by metamerism. Inkjet printers do the mixing of colors under a specific light source, resulting in a modified appearance of original and copy under different light sources. One way to minimize metamerism in printing is by first measuring the spectral reflectance of an object or reproduction using a color measurement device. Then, one selects a set of ink compositions corresponding to the color reflectance factor, which are used by the inkjet printer for the reproduction. The process is repeated until original and reproduction present an acceptable degree of metamerism. Sometimes, however, one reaches the conclusion that an improved match is not possible with the materials available either due to gamut limitations or colorimetric properties. See also Tetrachromacy Hyperspectral imaging References R.W.G Hunt. The Reproduction of Color (2nd ed.). Chichester: John Wiley & Sons, 2004. Mark D. Fairchild. Color Appearance Models Addison Wesley Longman, 1998. External links Java applet demonstrating metamers Stanford University CS 178 interactive Flash demo demonstrating color matching. Color