The phenomenon of Color is ever present in our daily lives, yet our understanding of Color is suprisingly limited.

So, what is Color? The color of anything in nature depends on the kind of light that it sends to our eyes. Our eyes can only see visible light, a form of electromagnetic energy, which sends out waves similar to the waves a rock makes when  tossed into a still pond. There are many kinds of electromagnetic energy waves, such as x-rays (shortest), ultraviolet rays, visible light, infared rays, and radio waves (longest). The visible spectrum is only a narrow sliver of the electromagnetic spectrum.

Light is essential to our perception of color. The apparently white light from the sun actually contains all of the possible color variations. Just as each portion of the electromagnetic spectrum has a corresponding wavelength, each color in the visible spectrum has its own wavelength. Reds have the longest wavelengths, and deep purples have the shortest. The color of an object depends on what type of light is hitting it, what colors are absorbed by the surface of the object, and what colors are relected back to our eyes.

The eye itself is similar to a camera because it has a lens to focus rays of light, an iris which opens and closes regulating the amount of light passing through, and film (retina) which responds to the variety of light that strikes it. Our eyes have the ability to see color because they have light sensitive receptors called cones and rods, located in the retina. The cones are sensitive to the colors (hues) and the rods are sensitive to the amount of light (values). The rods are more sensitive than the cones, and that is why we can see objects at dusk, but they seem to have very little color value. The rods and cones are connected to the optic nerve which then relays the information to the brain for interpretation. And we think computers process alot of information!

In an attempt to describe color, several models have been developed, each contributing to our Understanding of Color. The reason that there are so many different ways to describe color is because some colors rely on the mixing of opaque paint pigments, some colors are mixed light, and some are mixed transparent printing inks

Pigment Color The traditional color wheel for painters has twelve colors, three primary colors, three secondarycolors, and six tertiary colors. The primary colors for pigments are red, blue and yellow. Mixing the primariy colors creates the secondary colors. Red mixed with blue creates violet, red mixed with yellow creates orange, and yellow mixed with blue creates green. Mixing the primary colors with the secondary colors creates the tertiary colors; red-violet, red-orange, yellow-orange, yellow-green, blue-green, and blue viloet.

Additive Color (RGB) The primary colors in light however, are red, green and blue. This color model is called Additive Color, because it begins with black and adds light gradually to eventually create white. This theory states that adding all of the pure primaries together creates white light. A color wheel for additive color shows that mixing the primaries still creates secondary colors, however they are quite different from the pigment color wheel. Equal amounts of red light mixed with green light creates yellow, green mixed blue creates cyan, and blue mixed with red creates magenta. The remaining colors in the visible spectrum are created by combining unequal amounts of red, green and blue. Additive color is what is used for computer monitors, televisions, and is what our eyes see in nature.

Subtractive Color (CMYK) The offset printing proceess produces realistic looking full color photographs by using only four colors. To understand printing, we must begin with the white sheet of paper that that reflects white light (RGB). In order to see colors on the sheet, we must subtract (absorb) portions of the red, green and blue light so the reamaining light reflects the desired color. When blue ink is printed, we see it as blue because it is absorbing red and green light. So in this color model we begin with white, and gradually subtract reflected light to create black. Interestingly enough, the primary colors for subtractive color are the secondary colors in the additive color model; cyan, magenta and yellow. In theory, the combination of these three colors should create black, but due to the limitations of ink pigments, a fourth color, black, is added to give the photographs realistic looking shadows and true blacks.