As a communication designer, it is essential to know when to use RGB vs CMYK.
A good rule of thumb is anything dealing with the web should always be in RGB and printed material should be in CMYK. But it’s important to know WHY.
- On one hand, computer monitors give off colored light known as RGB (CMYK is colored ink). Computer monitors have a larger color gamut than printing, which is why a computer can display a million more colors than what can be achieved with printing.
- On the other hand, printing deals with absorption and reflection of wavelengths of which is perceived as color (CMYK). Printing also has its own limited color gamut.
A lot of times people will note that something looked different on screen than it does on paper and it is because of the different color ranges that computer monitors and printing allows.
To go into further depth, RGB colors are also known as “additive color”, because there are no colors and the colors are being added together to achieve further colors or until the outcome is white (look at the color chart image directly below, the inside color is white because it is all the colors added together).
This is because our eyes receive no reflected light and they perceive the color to be black. However, portions of red + green + blue are added the outcome is the CMYK colors as shown below.