Working in a design agency, clients often ask what RGB and CMYK mean. Whether we’re working on website design, logos, or brochure design, this question is relevant. As such, we figured we’d pass along our best definitions to you.
RGB and CMYK are different color modes. RGB stands for “Red, Green and Blue” while CMYK stands for “Cyan, Magenta, Yellow and Black.” Images and graphics need to be saved in one of these modes to look and perform correctly depending on the media they are used in.
RGB
This is the color space for all digital visuals. When an image is saved in RGB, the colors you see are created by mixing red, green and blue light in the device screen on which you are viewing the images. This mean that if you’re seeing a full-color photo on your computer screen, all the colors in the photo are created by tiny lights displaying the RGB colors in different levels of brightness. The settings for each color range from 0 (no light) to 255 (full light).
Here are examples of RGB color values:
Black: R0 G0 B0
White: R255 G255 B255
Opus Purple: R131 G0 B46
CMYK
This is the color space for all printed visuals. CMYK graphics are created by mixing cyan, magenta, yellow and black ink or toner to create all other colors. A full-color photo, for example, is the result of tiny dots — invisible to the naked eye — printed in these four colors. What we can see is the mix of the colors.
Here are examples of CMYK color values:
Black: C0 M0 Y0 K100
White: C0 M0 Y0 K0
Opus Purple: C0 M100 Y45 K55
RGB vs CMYK: Why you should care
You can imagine the problems saving an image in the wrong color space could cause:
- An infographic is saved as CMYK, and you are trying to display it on a website. Either your computer/browser won’t display the graphic at all, because it doesn’t know what CMYK means, or it will display the graphic but the colors will look off. If your image is actually displayed it might appear more fluorescent than what you expected.
- You are sending a logo design that is saved in the RGB color mode to be printed on an offset press for inclusion in a company report. The press has four buckets of ink ready to print your logo: cyan, magenta, yellow, and black. But when you send an RGB image to the printer, it won’t understand color “language” and will be unable to print the image. This issue is a real problem with offset printing. Digital printers can often at least produce a printout for you — but your logo colors might look “off.”
How to change the color mode of an image
Using an image editing software such as Photoshop, open your file and change the color mode to the correct one, depending on the media in which you are publishing your image.
