We humans perceive color when light enters the eye and is detected by the multitude of cells that make up the retina. The effect that light has on the individual cells is then sent to the brain where it is interpreted. Each cell provides one tiny piece of the puzzle that our brain will assemble into a complete image. The light entering the eye is the result of either light reflected by objects or light being emitted by objects.
Generally speaking, the Sun is the source of most of the light that enters our eyes during daylight hours. The Sun emits light that we can see and also light that we cannot see but we need only concern ourselves, with light that we can see. Since it is not wise to look directly at the sun, practically all light entering our eyes is reflected by the objects that surround us.
The Light that finally reaches our eyes can be vastly different from what was originally emitted. When light is reflected, some of the light may be absorbed rather than reflected. Also, Light, may pass through objects that filter out some of the light.
Light, as we perceive it, is a composite of energy consisting of different frequencies and is called the "Visible Light Spectrum."
Sir Isaac Newton first demonstrated that light is the source of color in 1666. Sir Isaac passed a beam of sunlight through a glass prism, producing a rainbow of hues from the visible spectrum.
A prism separates the light entering it by bending the various components of the light at different angles according to it's frequency. Assuming that the prism neither absorbs or reflects any of the light that is passing through it, the light exits the prism at different physical points and can thus be seen as separate colors.
Full spectrum light can be either reflected or absorbed by any object it strikes, or passes through, depending on the materials the object is made of or coated with. These materials are called pigments and absorb or reflect different frequency light, depending on their chemical composition. Pigments that absorb all light appear to be black. Pigments that reflect all light appear to be white. An object that appears to have a color, is actually void of the color it is reflecting, the color that can be seen, and is full of all the other colors because it is absorbing them.
Pigments can be mixed together in order to reflect or absorb specific colors. An example of this would be mixing various paint pigments together, in a base color, to get just the right color for your living room.
Back when I was in grade school, my Art Teacher introduced me to the concept of the Color Wheel similar to the one shown in the "AutoBead" opening screen. The Color Wheel represents the primary and secondary colors extracted from the full color spectrum by color pigments. This Color Wheel, then, is a representation of color reflected from primary and secondary pigments.
The Primary Color Pigments are:
| Red | Yellow | Blue |
Primary pigments, then, can be considered to be the most basic of color pigments and cannot be produced by mixing other primary pigments. When all three primary colors are mixed together, all light in the visible spectrum is absorbed. The result is black.
Mixing Primary Pigments in various proportions can produce reflective media that can be used to provide all colors in the visible spectrum. Mixing them two at a time, in equal amounts, produces reflective media that provides the secondary colors.
The Secondary colors are:
| Orange | Equal parts of Red and Yellow |
| Green | Equal parts of Yellow and Blue |
| Purple | Equal parts of Blue and Red |
The third type of color produced by mixing various pigments are the Complimentary Colors.
Primary Pigments cannot be used for Printer Inks because each of the three primary inks would absorb all color except their own. If any two Inks, made with primary pigments, are mixed, all primary colors would be absorbed.
Inks made using Complimentary Pigments can be used, however. Complementary pigments reflect rather than absorb primary colors. Mixing two inks made with complementary pigments results in a new color because light is reflected in proportion to the amount of each ink used. Mixing equal parts of any two such inks results in a primary color can be achieved.
Inks made using Complementary pigment absorb only the unwanted primary colors.
| Ink Color |
Primary Ink Absorbed |
Primary Ink Reflected |
| Cyan | Red | Blue & Green |
| Yellow | Blue | Red & Green |
| Magenta | Green | Blue & Red |
Cyan and Magenta, mixed in equal parts, absorb Red and Green leaving Blue. Magenta and Yellow, mixed in equal parts, absorb Green and Blue leaving Red. Yellow and Cyan, mixed in equal parts, absorb Blue and Red leaving Green.
Combinations of unequal subtractive amounts of the complimentary colors produce intermediate colors. Mixing all three complementary inks in equal portions absorbs all colors and, thus, produces black.
White cannot be produced by mixing complimentary colors because the ink absorbs color rather than reflecting it for the eye to see. To produce white, or the effects of mixing white with other colors, a Printer transfers NO ink to the paper. In this way, it produces the colors it needs for dithering, anti-aliasing or producing lighter hues of the complimentary color mix it is using.
To produce black, all colors must be mixed in equal amounts with no dithering.
Mixing all three colors together to produce black would be a very wasteful thing to do in terms of ink. For this reason, all color, ink jet printers have a black ink tank as well as one or more tanks for the three complimentary colors Cyan, Yellow and Magenta. The printing process described here is identified by the acronym CYMK and is common to most ink jet printers. The K stands for black.
Shades of gray are produced by dithering the black ink and interspersing dots of no ink, letting the media show through. This conserves the color ink for producing colors other than black and shades of gray.
Thumb Rule:
To accurately reproduce the color of an image, using a color printer, "bright white" paper should be used.
The whiteness of a paper is indicated by a number representing the percentage of light reflected from it. Paper that reflects 100 percent of the light that strikes it would be very difficult, if not impossible, to achieve. For color printing a plain paper, sometimes called "Bright White", with a brightness number of 90 or higher is acceptable. There are special paper that do better, but they are expensive in comparison to the "Bright White" papers.