Many involved in the color reproduction process are learning about color the hard way, through trail and error – often at great expense. The information in this book is intended to provide an understanding of basic color principles essential for making informed decisions during the color reproduction process.
It is important to know what color is a visual sensation that involves three elements – a light source, an object and a viewer. Without light, color would not exist. Light that appears white to us, such as light from the sun, is actually composed of many colors. If visible light is divided into thirds, the predominant colors are red, green and blue, which are the primary colors of light.
There are only two ways of reproducing color – additive and subtractive. Additive color involves the use of colored lights. It starts with darkness and mixes red, green and blue light together to produced other colors. When combined in equal amounts, the additive primary colors produce the appearance of white. Subtractive color involves colorants and reflected light. It uses cyan, magenta and yellow pigments or dyes to subtract portions of white light illuminating an object to produce other colors. When combined in equal amounts, pure subtractive primary colors produce the appearance of black.
It is the subtractive process that allows everyday objects around us to show color. For example, a red apple really has no color. Colorants in the apple’s skin absorb the green and blue wavelengths of white light and reflect the red wavelengths back to the viewer, which evokes the sensation of red. All color printing processes use the subtractive process to reproduce color. Printing presses use transparent color inks that act as filters and subtract portions of the white light striking the image on paper to produce other colors.