What’s the difference between RGB and CMYK color systems?

The difference between RGB and CMYK is one of the most common questions asked about color in design. 

But why? 

In this post, we’ll take a look at the difference between them and why it’s important to know which one to use when.

Before we begin, let’s get this out of the way:

  • CMYK stands for Cyan, Magenta, Yellow, and Black
  • RGB stands for Red, Green, and Blue

Light and Color

As you might already know, color is only visible with light. If there is no light, we don’t see color at all. Light is made up of all the colors, which we call the color spectrum. 

When we look at a green plant, light is being absorbed, except for green light waves. Green is being reflected and that is why we see the plant as green. A white piece of paper is not absorbing any light and as it reflects all the colors, we only see white. 

On a screen, red, green, and blue light pixels make up every color we see. 

What’s the difference between CMYK, RGB, and Primary Colors?

The most confusing thing about CMYK and RGB is that neither of the two is made up of the usual red, yellow, and blue. As kids, everyone learns that the primary colors are red, yellow, and blue. Due to this way of teaching in primary schools, most adults live their lives assuming that red, yellow, and blue are the primary colors.

Artists and designers, on the other hand, learn early on in their careers that color is more complicated than that.

CMYK vs RGB

Additive and Subtractive Color Systems 

Colors are organized into systems. The primary school color trio (blue, red, and yellow) is a color system. Yet, it’s not the most effective when it comes to design.

There are two main types of color systems, additive and subtractive. 

  • Subtractive color systems are those that mix colors by layering one to another, essentially subtracting the number of color wavelengths reflected on a surface. This applies to pigments, paints, and so on. 
  • Additive color systems are those that mix color by layering lights, therefore adding color wavelengths.
  • CMYK is a subtractive color system
  • RGB is an additive color system.

Technically, you could have any number of color systems, but these two are used universally because they are the best foundation to create any color of the spectrum.

To better understand the three color systems, simply remember this:

  • Red, Yellow, Blue is the color system taught in elementary schools.
  • CMYK is the color system for paints, pigments, and other physical color substances.
  • RGB is the color system for light, essentially digital screens like computers, phones, etc.
  • Just as a bit of bonus information, Pantone has its own color systems

RGB vs CMYK

The colors in CMYK are Cyan, Magenta, Yellow, and Black. When the first three colors are mixed together, they technically make black. It’s not a pure black, that’s why inks always have K, which is a better black than mixing cyan, magenta, and yellow.

The colors in RGB are Red, Green, and Blue. When these are combined, they make white. Remember that these are the colors that combine to make what you see on screens. 

If you look closely at the visual above, you’ll see that the secondary colors of CMYK are red, green, and blue. And the secondary colors of RGB are cyan, magenta, and yellow. 

When to use CMYK and when to use RGB

So, when do you use RGB and when do you use CMYK? 

All digital designs should be created in the RGB color system. If you are designing for print, then you should change the settings of your design program to the CMYK system.

What happens if you design in RGB and forget to switch to CMYK before printing? 

  1. If you print something on your home printer you might notice that the color on the paper is not the same as the one on the screen. 
  2. If you sent it to a printing shop, they will change it to CMYK for you but there will be color differences from what you see on your screen.
  3. If your printing shop cares for your professional career, they will remind you to switch to CMYK on your program and readjust color tonalities.

Some newer printers automatically adjust from RGB to CMYK but you should still always work with CMYK when the project is meant to be printed. Especially if there are brand colors that need to be consistent from screen to print. 

For a brand, the tone of green on their website has to look exactly the same as on their printed flyers. The only way to match them is to switch to CMYK and adjust BEFORE printing.

This is Just The Beginning

Colors are a big topic when it comes to design. There are so many levels of knowledge. In this post, we looked at the difference between RGB and CMYK and when to use each system. If you’re looking for tips and ideas on how to pick colors for your design, you can read our color guide.

Do you have any thoughts on why we use two different color systems? Please share in the comments.