Types of Color
When working with digital images there are two primary types of color systems you are going to be interacting with: Additive
Additive color is the kind you see on TV sets and monitors. It starts with black when the pixels are unlit and then selectively lights pixels that are red, green and blue (RGB) at different levels. This gives a very wide color spectrum with a huge amount of diversity in color. When all three colors of pixels are fully lit, white is produced.
Because they produce their own light, monitors are extremely good at controlling the colors that they create and their color spectrum is very large, up to 16 million different colors. This is larger than any subtractive color system and can produce a number of colors that can't possibly replicated by printers in any capacity.
Color Spectrum of Various Devices
Other devices such as scanners and cameras also use RGB systems to measure colors that they capture to make it easier to calibrate on other digital mediums.
Subtractive color systems start out with their maximum brightness, usually on a white piece of paper, and then color is added which selectively darkens the page with specific colors. When all these colors are combined it creates black. Printers and color mixes like Pantone are subtractive color systems. The most common subtractive color system is CMYK, or Cyan, Magenta, Yellow, and the Key (black). The three colors can be combined to make a large spectrum of colors and then is shaded by the Key which is black ink. Because the ink does not produce its own light, the brightness of subtractive color systems have specific limitations in the range they can create and are then always much smaller than most modern additive color systems. This is why prints normally turn out significantly darker than on screen images.
Close up image of an inkjet printed image. The Magenta and Cyan dot angles are labeled.
When you print something, the ink comes out in microscopic dots (halftones
) at such close proximity it creates the illusion of multiple colors. The ink droplets are all a uniform color unlike computer pixels which have a range of colors based on their brightness. Each color of ink comes out at a different angle and this is what creates the illusion of a consistent image.
Another subtractive color system is the Pantone Management System. Pantone colors are precise mixtures of very specific colors which are easy to replicate. Pantone colors have the widest spectrum of colors for printed media and because they are coded it is easy to consistently find and create the same colors. However, this color system is not very accessible to most people as the mixtures which create their colors are trade secrets and are not used by consumer products. To access Pantone colors you normally have to go through a printer or manufacturer unless you buy some fairly expensive tools.