Modern color imaging is based on the 19th century trichromatic color theory of color vision proposed by Young. The first color picture was made in 1861 by James Clark Maxwell using three pieces of black & white film exposed sequentially thru red, green and blue filters. Black & white slides were prepared and projected on a screen, one projector equipped with a red filter, another green and the third with blue. When the three images were superimposed, the world saw the first color photograph. Gabriel Lippmann demonstrated color photographs, no filters, using an interference process. Dr. Land of Polaroid fame demonstrated a two color method using white and red light. The Lippmann and Land methods are curiosities that were never commercially practical. The Maxwell method prevails today.
TV and TV projectors and computer screens use an additive color method which entails fracturing a vista into tiny points of red, green, and blue and displaying them for viewing. This method controls the intensity of each of the millions of red, green and blue pixels (picture elements) that comprise the image. While this works for projected and screen displays, it fails when the image is presented as ink, dye or pigment on paper.
For images on paper we resort to dots of color using the subtractive primaries. These are the complements of the additive primaries. Complement in this usage is “opposite”. The complement of red is cyan, a red light blocker. The complement of green is magenta, a green light blocker. The complement of blue is yellow, a blue light blocker. The CMY system uses the subtractive primaries to control how much of the three primary colors will reflect from a surface.
Why cyan, magenta, and yellow? Each consists of two colors. Cyan is blue + green. Magenta is red + blue. Yellow is red + green. Each acts as a filter that limits how much of its complement (opposite) will be reflected. In other words, cyan is a red blocker, magenta is a green blocker and yellow is a blue blocker.
These subtractive primaries work OK, but they have a deficiency. They should when overlapped make black. Sorry to report that they can only make dark gray. This is because the cyan dye/pigments and the magenta dye/pigments are slightly off hue. Nobody yet has found the right colors. Yellow however is very good. Because the three when overlapped fail to make black, we add black when we can, and this adds contrast. The added black is called by the printing industry a “Kicker”. Thus the term CMYK.
It’s OK to play around, changing the colors of the inks used in your inkjet. Just remember, some of the best minds in the business have been working on this for more than a few hundred years. Not to discourage you. Who knows what will come out of experimentation! I think, you will need to change the software and the hardware to get improved results. Also, high end printing (lithography and printing press) often add additional colors to the CMYK as enhancements.
