Color matching is very important because not all of the colors we can see in nature can be reproduced. Our computer monitor re-creates colors by mixing Red, Green and Blue (RGB) lights. Printing traditionally re-creates colors by mixing Cyan, Magenta, Yellow and Black (CMYK) inks.
The chart to the right shows the amount of colors each process can re-create. Color matching is important because as you can see, your monitor cannot display every possible color you can find in nature, and a printer can re-create even less. It is important to remember that it is difficult to get extremely vibrant colors in CMYK printing.