If you have ever created printed materials, you may have heard the term “CMYK”. CMYK represents Cyan, Magenta, Yellow, and Black. These colors combine in four-color process printing to approximate the visible color spectrum. The colors layer on top of each other during the printing process to achieve the final full-color image on paper. The complexity and expense of a printing job is greatly influenced by how many colors are used in the creation of the design, so a one-color print will be less expensive than one using all four colors.
Pantone brand colors are the most universally accepted color standard. With Pantone, you can achieve colors not possible in CMYK, and also print a one-color job in something other than black. Printers use a special mix of ink to achieve the color needed. There are over a thousand Pantone colors to choose from in order to make your design stand out. Incidentally, Pantone also has developed color standards for fabrics, carpets, plastics and more to further help you control your brand and your color environment.
RGB stands for Red, Green and Blue. This is the color model used for the screen or on the web. Some colors displayed on a computer monitor in RGB may not match those printed with CMYK or Pantone since the environment they are created in and their constituent colors are fundamentally different. It is important to note that all three of these color modes have at least some colors that cannot be achieved in one or both of the other color modes. A comparison can be seen at Wikipedia.