IF you never have to deal with CMYK, consider yourself lucky! An old saying I recall that's kind of amusing: God (I prefer DOG) created RGB. Man created CMYK: what would you rather use?
CMYK aka the devils color space
A related question; which profiles in my Windows color directory can I throw out before an Adobe program starts to complain?
Met vriendelijke groet, Ernst
http://www.pigment-print.com/spectralplots/spectrumviz_1.htmJanuary 2016 update, 700+ inkjet media white spectral plots