color sep page2

The CMYK Color System
Cyan - Magenta - Yellow - Black

In the print industry, cyan, magenta, yellow and black are used as the primary colors. When you mix all the colors, the result is gray. If you look at a printed page with a magnifying glass you might see something like the illustration below.

http://64.19.142.10/www.colormatters.com/images/images1/ct-cmyk-closeup.gif_hyuncompressed

The color systems used by scientists and artists are entirely different. An artist will mix blue and yellow paint to get a shade of green; a scientist will mix green and red light to create yellow. The printed page in a magazine is yet another system.
It's important to define the two different kinds of color that we see in the world as the first step in understanding color systems.

First, there's the color you can touch, such as the skin of an apple or a painted wall. These colors are part of the surface of an object. Next, there's the color you can't touch, such as a beam of red light and the colors produced by your computer monitor. Colors generated by light are part of one color system. The tangible colors which are on the surface of objects or on the printed page are another color system.

A common color mode, RGB stands for the colors of Red, Green, Blue. Add red, green, and blue light to create white light. Because you ADD the colors together to get White, we call these RGB colors the addtive primaries. Colors on screen are displayed by mixing varying amounts of red, green, and blue light.
RGB is the most common color mode used when creating graphics, even though graphics to be commercially printed are eventually converted to CMYK mode, the colors used in printing inks.
Keep in mind that RGB refers to an on-screen color mode. Mixing red, green, and blue inks or red, green, and blue paints is not going produce white.

As you might suspect, there are different types of color. Now is when you can throw the color wheel out the window.

RGB Color:

This is color based upon light. Your computer monitor and television use RGB. The name "RGB" stands for Red, Green, Blue, which are the 3 primaries (with green replacing yellow). By combining these 3 colors, any other color can be produced. Remember, this color method is only used with light sources; it does not apply to printing.

CMYK Color:

This is the color method based upon pigments. "CMYK" stands for Cyan, Magenta, Yellow, and Black (its what the K stands for). Using these 4 colors, most other colors can be achieved. Unfortunately, CMYK cannot reproduce the same amount of colors as RGB can, which is why yellow-greens sometimes look a bit muddy when printed.
This is the method used by printers the world over, and is also a clever way of mixing paints.

Pantone (PMS) Color:

This is yet another printing color method. PMS stands for "Pantone Matching System," and is a large list of specially mixed colors made by the Pantone Corporation. Instead of using CMYK to create colors, the pigments are created individually for purity.
For example, if I wanted to use a Red-Violet color, I'd pick PMS 233M. The color would be made exclusively for my project and would always print exactly how I want.
The only drawback to using PMS colors is that they're only useful for projects with few colors. They're also expensive.

In offset printing, a spot color is any color generated by an ink (pure or mixed) that is printed using a single run.

The Pantone Color Matching System is largely a standardized color reproduction system. By standardizing the colors, different manufacturers in different locations can all refer to the Pantone system to make sure colors match without direct contact with one another.
One such use is standardizing colors in the CMYK process. The CMYK process is a method of printing color by using four inks — cyan, magenta, yellow, and black. A majority of the world's printed material is produced using the CMYK process, and there is a special subset of Pantone colors that can be reproduced using CMYK . Those that are possible to simulate through the CMYK process are labeled as such within the company's guides.
However, most of the Pantone system's 1,114 spot colors cannot be simulated with CMYK but with 13 base pigments (15 including white and black) mixed in specified amounts.
The Pantone system also allows for many special colors to be produced, such as metallics and fluorescents. While most of the Pantone system colors are beyond the printed CMYK gamut, it was only in 2001 that Pantone began providing translations of their existing system with screen-based colors. (Screen-based colors use the RGB color model — red, green, blue — system to create various colors.) The Goe system has RGB and LAB values with each color.
Pantone colors are described by their allocated number (typically referred to as, for example, "PMS 130"). PMS colors are almost always used in branding and have even found their way into government legislation and military standards (to describe the colors of flags and seals). In January 2003, the Scottish Parliament debated a petition (reference PE512) to refer to the blue in the Scottish flag (saltire) as "Pantone 300". Countries such as Canada and South Korea and organizations such as the FIA have also chosen to refer to specific Pantone colors to use when producing flags. U.S. states including Texas have set legislated PMS colors of their flags. It has also been used in an art project by the Brazilian photographer Angelica Dass which applies Pantone to the human skin color spectrum.