What’s in a color? Well, a lot of things, and while both CMYK and RGB are color spectrums, they can be very different when you submit your artwork to be printed. It may seem like an issue that should be easily fixed, or at least easily overcome, but just like in homebrew, once you make something, you cannot unmake it.
To stay on the beer theme, knowing the difference between CMYK and RGB might feel a bit like knowing what a Bohemian Pilsner is compared with a German Pilsner. At the end of the day they are both Pilsners, but how they are made varies.
RGB is the name for the basic color spectrum that we see in our digital lives every day: Red, Green, Blue. These three colors combine to make the text you are reading, the images you interact with, the apps you open and use. Our screens use pixels to display colors to us. Each pixel has three “subpixels” - red, green, and blue. Each of these subpixels lights up with different intensities based on whatever color the larger pixel is programmed to display.
You might have seen RGB colors displayed as a set of numbers, if you’ve ever done any light Photoshop work. RGB values are shown as a series of numeric values, for 0 to 255, and since zero has a value in coding, this number set means there are 256 levels that each of these three colors (Red, Green, and Blue) can be displayed as. For example, the RGB code for Black is:
Meaning, zero light is being generated. On the other side of that, you have the code for White, which is:
Meaning, each pixel is at 100% brightness. If you want yellow, you’d set your RGB value at:
RGB is a simple color method that is easily translated to digital devices and handled well by these tiny pixels. Not to complex, and yet, able to render so much color. CMYK is a different animal. This is the color format most used for print work, as it has four colors to it - Cyan, Magenta, Yellow, and Key (Black). The reason Key is used for Black, is because B is used for Blue in RGB, so the last letter in “Black” was chosen … K. Weird, we know.
CMYK is considered a subtractive color scheme, meaning in order to make lighter colors, we simply subtract some colors rather than adding them like in the RGB scheme. Also similar to RGB is the way CMYK is represented via a number system, but in this case, we use percentages. So, if we want something to print in Black, we use:
However, with CMYK, you can exhibit a range of black, unlike anything you can replicate in RGB. Here are some examples:
Cool Black: 60 . 0 . 0 . 100
Warm Black: 0 . 60 . 30 . 100
Designer Black: 70 . 50 . 30 . 100
You get the idea. So which color setting should you use for your project? Well, if your piece of future digital greatness will only be seen on your computer screen, RGB is the way to go. If you are working on something you plan to print, be sure to set your colors to CMYK before you start your project.
But wait - what if you have already crafted your new label or coaster artwork in RGB? Well you can’t go back and change things, unfortunately, so you will have to do some work to adjust for the color differences. If you’re working in RGB, you can check how the image will look when converted to CMYK by choosing View > Proof Colors, or using the shortcut Command Y (Mac) / Ctrl Y (Windows). So if you’re working for print, you’ll need to adjust the colors to avoid disappointment later. RGB colors tend to look more saturated on screen than CMYK colors do. Some small tweaks now in RGB will help your files print the way you intended them to when we receive them.