Color Modes
Understanding color modes will help you create digital files that are the most appropriate for the purpose of your design work. Here we will focus on the difference between color modes for web viewing and for printing.
COLOR for PRINT
What is color?
Color: a phenomenon of light (as in red, blue) or visual perception
that enables one to differentiate otherwise identical objects.
Also a hue as contrasted with black and white or
gray.
Miriam-Webster Dictionary
RGB Color Mode
- For computer displays
- Uses light to display color
- Red, Green, Blue
When CMYK Meet!
CMYK
- For printed material
- Uses ink to display color
- Cyan, Magenta, Yellow, Black
cyan, magenta, yellow, and black are known as the process colors.
Pantone or Spot Color Mode
- For printed material
- Uses ink to display color
- Specific colors to be reproducded accurately
- Swatch books show the colors and their formulas for the printer.
- Cyan, Magenta, Yellow, Black may be used as spot colors when assigned to vector art
Gamut or Range of Color
Color can be viewed in nature, on a monitor, and on paper or film. The medium used determines the range of colors, or gamut, that can be reproduced.
In addition, the gamut may be limited by factors such as the
- phosphors in the monitor,
- dyes on the film
- ink and paper used in printing.
The widest variety of colors is in the visible spectrum
as viewed in nature. This spectrum contains all colors that the human
eye can perceive.
A subset of these colors can be viewed on a computer
or television monitor.
These devices reproduce color by emitting red, green, and blue light.
Certain colors, such as the color cyan or a very bright yellow, cannot be displayed accurately on a monitor.
The llustration below shows the gamut of colors that can be printed using process color inks is primarily a subset of the colors that can be displayed on a monitor.
This means that although a monitor can display most printable colors (as in Photoshop's CMYK mode), many colors that can be displayed on a monitor cannot be printed using the four-color process.
The "!" icon that appears in the Photoshop color picker and in the Info palette when choosing certain colors indicates colors that are nonprintable, or out of gamut, for process color printing.
Comparing Color Gamuts
Because of physical difference in how various devices produce colors,
each scanner, display, and printer has a different gamut, or range of
colors, that it can represent.
The RGB color gamut can only display approximately 70% of the colors which can be perceived
The CMYK color gamut is much smaller, reproducing about 20% of perceivable colors.
The spot color gamut achieved with premixed inks
(like the Pantone Matching System) is also smaller than the RGB gamut.
Note that there are many PMS colors which don't have matches in the CMYK
color gamut.
In the world of print, the only color modes acceptable are CMYK or Spot color.