CMY and CMYK are the spaces generally used to print colors. The problem is these spaces
are extremely device dependent. The kind of paper, ink, and printer
technology used in the process, heavily impact the final color quality.
In this context CMY and CMYK spaces have been added to our conversion tables only because
they represent very popular color information in the computer world.
The very simple transforms used to convert RGB data to CMY and CMYK, are fine just for
very basic color printing. For professional application, or everywhere color presentation
is critical, an accurate printer profiling (characterization of a device dependent
space to a device independent one) must be used.