http://www.sdsc.edu/0/SDSC/Geninfo/Fun/color.html (World Wide Web Directory, 06/1995)
Since NTSC Colors are prone to errors, television manufacturers, have developed the above colorbar to adjust television sets. It contains the major primary and secondary colors, plus black and white.
Computer black is the absence of all of the primaries. Computer black with a value of 0,0,0 is referred to as superblack and is used for matting or keying in video effects. Superblack does not render well to video. Instead of appearing black, it has a light gray appearance. Therefore, the standard NTSC colorbar black, which is 8% gray, should be used. Video black will appear blacker on video than superblack.
Computer white, being a mixture of fully saturated red, green, and blue, is the brightest color. It requires the least amount of de-saturation prior to videotaping.
Since it is a mixture of the brightest computer primaries, red and green, computer yellow is the brightest of all the computer secondary colors. Computer yellow appears slightly greenish at full saturation and can be modified by lowering the green values slightly. Colorbar yellow appears bright although it is mixed with blue.
Computer cyan is a secondary color with almost the same brightness as computer yellow. Saturation levels should be controlled and de-saturated before transferring to video. Colorbar cyan still appears as bright as computer cyan though it is lower in saturation and mixed with a small amount of red.
Computer green is the lightest and brightest of all the computer additive primary colors. It appears yellowish at full saturation rather than what is traditionally thought of as green. Prior to videotaping, it nees to be toned down by lowering the level of saturation. The addition of a little red makes it appear more yellowish and the addition of a little blue makes it appear more bluish. Traditional deep greens are difficult to mix on the computer.
Computer magenta results from the mixture of primaries red and blue. It should be de-saturated before transferring to video. Since it is partly made of red, it has a tendency to bleed and cause blurring effects around its edges. A small amount of green will make it the standard colorbar magenta.
Computer red, though good looking on a high resolution monitor, cannot be properly transferred to video. It creates unwanted color artifacts such as color bleeding, or halation, where a halo appears around the color. To avoid this, lower the saturation to the video safe colorbar levels. Also note that at full saturation, this red is not what is thought of as red. It is actually a red-orange and needs a slight amount of blue added to obtain a traditional red. In video, the color red should be avoided as much as possible.
Computer blue is one of most popularly selected colors. It is the least bright of the primaries and requires the least amount of de-saturation before transferring to video. It is important to note that fully saturated computer blue is lost on a black background, especially a superblack background. Placed on a lighter gray background, it will appear much brighter.