The color matching process reproduces any given color on demand, regardless of color formatting. Technically, true color matching is not possible because of environmental and material factors. However, there are established color matching standards such as the Pantone color matching system, which allow for highly accurate color matching. Color formats such as CMYK, which are known for being inconsistent, are much more difficult to accurately match.
In North America, the most established color matching standard is owned and managed by the Pantone Corporation. The Pantone Color Matching system is based off of a physical swatch which is distributed by Pantone Inc. This physical swatch has unique recipes for all of its colors, which are based on mixing a smaller set of base colors in specified ratios. Since the swatch is only distributed in a physical form, there is a clearly defined standard to check against. Although a 100% match is not attainable, this solution ensures a high level of accuracy.
CMYK colors are challenging to reproduce accurately. The main reason is because of the inconsistent nature of CMYK. CMYK color is made up of mixing Cyan, Magenta, Yellow, and Black in varying ratios in order to achieve a target color. This color formatting is far more susceptible to variation because of its unique screen production process. Inks are not mixed in advance of the press run, rather a series of dots in varying ratios are printed over each other during the production run. Factors such as humidity, static, electrical current, among others can significantly affect the results. A common strategy that printers use for color matching in CMYK is to print multiple tests, and calibrate accordingly. This strategy is much easier to do with digital printing than with offset printing.
Some of the more advanced production presses have software that is designed to help with the color matching process. This is particularly common with newer digital presses. These digital presses have a color scanner which helps calibrate the press to match a desired color. For example, an individual may have a blue business card that was printed in CMYK previously. Since there is not actual standard to compare against, the only logical target are the existing business cards. One of the business cards can be scanned before the production run begins. After the initial calibration is complete, a test print can be produced. If the test print is not close enough, further calibration can be done. This process is dynamic, and requires testing. Even with this added labor, the printed results still might not accurately match the desired color. Most digital printing companies will refrain guaranteeing an exact match.
Color matching is only possible to a certain degree of accuracy. With established color matching systems such as Pantone, the degree of accuracy can be very high. However, with other color formats such as CMYK, the results can vary widely. New software and hardware technology is improving the accuracy of CMYK. However, a close color match is unrealistic with CMYK despite the recent advances.