Christine Kelly, age 13, of Columbia, Tenn., for her question:
WHAT ARE THE CHARACTERISTICS OF COLOR?
Three basic terms are used to describe colors in objects: hue, saturation and lightness. These are called the characteristics of color.
Hue is the name given to a color. Red, as an example, is a hue. But there are hundreds of different kinds of red. Saturation is the amount of hue in a color. There is a great deal of red in vermilion, for example, but not much red in pink. Lightness indicates how light or dark a color is. Pink is almost as light as white, while vermilion is much darker.
About 300 different colors can be accurately described. Experts say there are actually about 10 million different colors all together. Each color differs from the others in some degree of hue, saturation or lightness.
Some colors have special names because they differ so much from the colors suggested by their hue names. Brown, for example, is actually orange or red with low saturation and low lightness. Olive is yellow or yellow green with high saturation and low lightness. And pink is really bluish red with low saturation and high lightness.
Albert Munsell, an American painter who lived from 1858 until 1918, worked out what is called the Munsell Color System. Using the term "value" for lightness and "chroma" for saturation, the plan arranges all colors on the basis of their appearance.
The National Bureau of Standards has worked out a system for naming colors. They have defined more than 270 colors and related 7,500 other common names to the basic list.
There are only three primary colors: red, yellow and blue. And there are only three secondary colors: orange, green and violet.
Color harmony is the use of combinations of colors to produce a pleasing effect.
There are no set rules of color harmony because too many factors must be considered. But complementary colors, or the two colors that are opposite each other on a standard color wheel, go especially well together.
There are three complementary color combinations the two colors that are opposite each other on a color wheel: red and green, yellow and violet, blue and orange.
A color scheme called a mutual complement combines five adjacent colors from the color wheel, such as blue green, green, yellow green, yellow and yellow orange. These are also called analogous colors.
Light travels in waves, the same as radio signals. But light waves are the only ones we can see. Scientists have discovered that each colored light has its own wavelength. Violet light has the shortest waves we can see: 67,000 waves per inch. Red light has the longest visible waves. But even these waves are short: 33,000 per inch.