In this third and final chapter on color, we will address one of the major dilemmas that afflict graphic designers and creatives from all over the world: is it better to work in RGB or CMYK?

For the uninitiated, these two abbreviations refer to the two most common color models in digital graphics.

RGB is an additive color model based on three primary colors: red, green and blue. These three colors are mixed together in various ways to reproduce a broad array of colors. When the three colors overlap at maximum saturation they generate white. This color model is called additive because each color, when combined with the others, increases its brightness. The combination of different quantities of light produces all the colors of the color spectrum of reference. As it is closely linked to brightness, the RGB color model is mainly used for images and designs intended for devices that emit light, such as screens or monitors.

CMYK, on its part, is a subtractive color model. The primaries, in this case, are cyan, magenta and yellow with the addition of black (Key color) for technical reasons. In this type of synthesis, the combination of the three primaries gives life to colors with progressively lower brightness. The combination of 100% CMY in the printing phase in a muddy dark color known as a composite black, while 100% K is not perceived as absolute black. To obtain rich black it is necessary to combine all 4 shades according to different percentages: based on the dominant color, it is possible to get warm, cold or neutral blacks. This color model is used for printing as it is based on the mixing of different quantities of ink.

RGB and CMYK have different purposes and uses that are difficult to integrate with each other. The color rendering of the former allows for bright and luminous shades that do not exist in CMYK. Furthermore, the chromatic results could vary depending on the device used. The same RGB or CMYK values may appear different on different screens and printers. In fact, each device can produce and reproduce only a certain subset of the visible colors defined by its gamut. The CMYK color space, for instance, has fewer hues than the RGB gamut. Colors that cannot be described by a certain color model are colled out-of-gamut colors.

Recap: RGB or CMYK?

Working in RGB for print files would entail, at the time of conversion for printing, the loss of brightness. Print results will be therefore different than expected. On the other hand, working with a limited gamut of CMYK for digital use would entail giving up interesting and original chromatic results.

Before choosing either one, ask yourself what do you intend to do with your design.