Form: Color Theory Color breakthroughs Our understanding of the properties of color is based upon Sir Isaac Newton's 1672 experiments with prisms, in which he described how light can be broken into a spectrum of colors. Observing these prisms, he noticed that different wavelengths of light produced different colors (as pictured below). Since Newton's time, we have developed increasingly sophisticated systems for categorizing the infinite range and relationships of color. Color theory can help explain how colors are differentiated and combined for artistic impact. A world of difference The differences between colors are created by variations in three basic properties: hue, saturation, and brightness. Hue is what we normally think of as basic color. Some hues are easy to tell apart, such as red and blue — but others may be more difficult to distinguish, as shown below on the scale of red and orange. Many of us would disagree where the red becomes orange on this scale. Saturation is what we might call the purity of a color. The red at the right end of the scale below is very saturated, but on the left-hand side, it is so tainted by another, darker color that it doesn't look like red at all. Brightness is the intensity of a color. The right side of the scale below is bright red, which becomes gradually washed out on the left until the red begins to resemble a pale pink. The three hardest-working colors Physicists have found that of the roughly ten million colors we can perceive, there are only three that are not composed of a mixture of hues. These are the primary colors: red, blue, and yellow. When mixed in equal parts in paint, the three primary colors produce a dark gray, approaching black. Notice in Carolyn Cole's painting Luna (below) how expressive just these three primary colors can be. Making the rest of the rainbow Carolyn Cole Mixing pairs of primary colors results in three ranges of secondary colors. The mixture of red and blue in varying proportions results in a range of purples. Blue and yellow produce a variety of greens. Yellow and red produce a spectrum of oranges. A secondary color can be any mixture of two primary colors, but lacks any amount of the third primary color. For example, green contains blue and yellow, but not red. Color for maximum impact Since red and green (made of blue and yellow) together contain all three primary colors, they are considered to be complementary colors. When shown side by side, complementary colors produce a striking optical effect. Flags and uniforms (soccer shirts, for example) are good examples of how the right combinations of primary and secondary colors can be eye-catching. In this simple diagram on the right — derived from an 1832 sketch by the French artist Eug? Delacroix — the arrows pointing from the primary color at one point of the triangle to the secondary range at the opposite side of the triangle indicate the complementary relationships. Flying colors Laura Fayer's painting Crossing the Glacier shows us how complementary colors can work together in actual practice. The red rectangle makes the acid green next to it seem to pop right off the canvas, and the less-saturated reddish rectangle to the far right seem sedate by comparison. Laura Fayer Next: Color in art