RGB vs CMYK: What's the Difference?

Designers in all industries have to work with color on a daily basis, but so do branding experts and professionals who are tasked with creating letterheads, presentations, and other documents that speak to their personality and expertise. 

So, while the theory behind color models—namely RGB and CMYK— is often overlooked, understanding them can help everyone be more creative and achieve professional results. 

The two primary color models are RGB and CMYK: RGB stands for red, green, and blue; CMYK stands for cyan, magenta, yellow, and black. You'll most often work with CMYK when working with printed materials, including magazines, brochures, and business cards. Meanwhile, RGB is the preferred color model for digital projects, including logos and websites. 

Most people know the basics of how to mix the primary colors to get to the color they want, so the "additive" approach used by the RGB model is considered very easy to grasp. On the other hand, cyan and magenta can throw you off from the start, and having four values to work with instead of three complicates things, making the subtractive model used in CMYK all the harder to learn. Yet, both are critical for professional designers to understand. 

If you work strictly with digital projects, you might be able to get away with never learning RGB. However, most professionals will need to work with print designs at some point. Understanding CMYK will make it that much easier to arrive at the ideal colors for your project and make sure they print the way you intend for them to. 

RGB is a color model that takes an additive approach, which means white is a combination of all primary colors, while black is the absence of light. The RGB model was developed explicitly for digital projects because of the way that screens display color. 

When written in RGB, a color is represented by three values, each one ranging from zero to 255. The first value represents red, the second green, and the final blue. The closer a value is to 255, the whiter it becomes. 

If you were to view a screen's pixels with a microscope, you'd see that each pixel is one of three colors consisting of red, green, or blue light. The closer a color is to white, the brighter the pixel gets as it blends all three colors together. This technique allows the retina in the human eye to perceive a wide range of colors, and, since today's screens consist of millions of pixels, they can produce extremely high-resolution images.

Screenshot of Adobe InDesign’s RGB color picker feature (Source)

CMYK is a color model that takes a subtractive approach, which means white is whatever the color of the paper or material is, while black is a combination of all the colored inks used by the machine. To print a design, machines lay down tiny dots of cyan, magenta, yellow, or black, each ranging from zero to 100 percent. 

All in all, CMYK cannot reproduce all of the colors that are possible to achieve with the RGB model, which is precisely why all of your print projects should be designed using CMYK. 

If you are using a design tool, switch to CMYK mode when working on a print project, or your designs are unlikely to turn out the way you'd expect. Likewise, when working with digital projects, switch to RGB to keep the mockups and designs consistent with the final product. 

Screenshot of a CMYK color picker dashboard (Source)

Understanding both RGB and CMYK is a must, especially for professional designers who are bound to work with a mix of print and digital projects. However, it's easy to figure out which color model is best based on your medium: 

Stick to RGB for digital projects, and CMYK for print media.