<P> Placed side by side as tiny dots, in partitive color mixing, complementary colors appear gray . </P> <P> The RGB color model, invented in the 19th century and fully developed in the 20th century, uses combinations of red, green, and blue light against a black background to make the colors seen on a computer monitor or television screen . In the RGB model, the primary colors are red, green, and blue . The complementary primary--secondary combinations are red--cyan, green--magenta, and blue--yellow . In the RGB color model, the light of two complementary colors, such as red and cyan, combined at full intensity, will make white light, since two complementary colors contain light with the full range of the spectrum . If the light is not fully intense, the resulting light will be gray . </P> <P> In some other color models, such as the HSV color space, the neutral colors (white, greys, and black) lie along a central axis . Complementary colors (as defined in HSV) lie opposite each other on any horizontal cross-section . For example, in the CIE 1931 color space a color of a "dominant" wavelength can be mixed with an amount of the complementary wavelength to produce a neutral color (gray or white). </P> <Ul> <Li> <P> A traditional color star developed in 1867 by Charles Blanc . The traditional complementary colors used by 19th - century artists such as Van Gogh, Monet and Renoir are directly opposite each other . </P> </Li> <Li> <P> The colors of the RGB color model, which uses combinations of red, green, and blue light on a black screen to create all the colors seen on a computer display or television . Complementary colors are opposite each other . </P> </Li> <Li> <P> The HSV color wheel has the same complementary colors as the RGB color model, but shows them in three dimensions . </P> </Li> </Ul>

Which of the following is not a pair of complementary colors