Printing In Color RGB and CMYK

A common problem when printing is getting the color correct.  Many times the color output from the printer differs somewhat from what we see on our computer monitors.  This is an unavoidable situation when it comes to printers and here is why:



Visible Spectrum vs RGB vs CMYK

There is a significant differnece in what is visiable to the human eye and what we are able to graphically reproduce.

The entire color area represents the gamut of colors visible to the human eye.

The yellow area represents the colors that fall in the RGB spectrum.

The blue area represents the colors that fall in the CMYK spectrum.

As you can see these areas do overlap but their are still colors that a monitor (RGB) can produce which a printer (CMYK) cannot, such as some yellows and greens.  As well as colors that are visible and can print but cannot be reproduced on a screen, like some blues.



The RGB Color Spectrum

The RGB (Red, Green, Blue) color system is considered to be an ADDITIVE system.  This is because you start with black and add colors together to achieve white.  This spectrum is used in computer monitors and television screens.



The CMYK Color Spectrum

The CMYK (cyan, magenta, yellow, black) color system is considered a SUBTRACTIVE system.   With all colors present you have to subtract color to achieve white.  This spectrum is used in print media.


The differences in these two color spectrum are what cause the shift in color representation from the computer monitor to a print document.  There are ways to compensate for these shifts, such as working in CMYK mode in Photoshop, but even this will not be 100% accurate.  Some colors will be more difficult to reproduce than others, a vivid red for example can be very difficult to accurately represent on a document.