CMYK or Cyan, Magenta, Yellow and BlacK is the color space used in the print world. This color space is actually the opposite space on the color wheel of RGB. As such, it was also used in film processing, which dealt with the recorded negative image, from which a postive print was produced. CMYK is also the basis for the Pantone Color Library, originally intended for print, and defines millions of specific colors by CNYK formula, unique ID, and name. Curelean Blue will always be the same color, as long as they manufacturer follows the specifications.
It should be noted that it is not always possible to accurately convert from one color space to the other, for a variety of different reasons. As a result, colors will not explicitly match in some cases (though they will be very close.)