The RGB and CMYK color models each serve different purposes. The RGB model is an additive model mainly used for digital design, while CMYK is subtractive and used for printing purposes. When comparing these color models, it's important to realize that these color models are not meant to work in the same space or for the same purpose. What you're really comparing is colored light versus colored ink, and the ability to display color in the medium.
What is RGB?
RGB is the color model of the digital color system. RGB stands for red, green, and blue, respectively, because the different levels of these colors are all we need to create any color on the visible color spectrum.
While many printing systems can now use RGB for fairly accurate print results, RGB is better used digitally because computer monitors are capable of displaying more colors than printing presses.
What is CMYK?
CMYK is a color model commonly used in printing. Also known as "four-color processing", it stands for cyan, magenta, yellow, and key (or black), and is a subtractive color model rather than an additive color model like RGB. In printing, CMYK reduces the brightness or reflected light of a white background. It subtracts the amount of white displayed by working through the levels of cyan, magenta, yellow, and key to get the desired color.
Convert between RGB and CMYK
RGB to CMYK can be converted using Adobe Creative Suite. However, if you already know whether your design will be digital or print, go ahead and build with the most appropriate color model. Digital projects (web graphics, emails, online advertising) should always be constructed in RGB format. Print projects (business cards, banners, t-shirts) should be built in CMYK.
Color Muse and the RGB color model
If you own Color Muse, you may have noticed that it outputs RGB - not CMYK - color values for scanning and matching. Color Muse does not support CMYK as this color space varies between available standards, RGB can be quickly converted in Adobe Photoshop.
