As you may have discovered through painful experience, computers aren’t great with color. Each device you use to create and print digital images “sees” color a little bit differently, which explains why the deep amber captured by your scanner may be rendered as chalky brown on your monitor yet come out as a fiery orange on your Epson inkjet printer. Since every gadget defines and renders color in its own way, colors are often inconsistent as a print job moves from design to proof to press.
ColorSync attempts to sort out this mess, serving as a translator for all the different pieces of hardware in your workflow. For this to work, each device (scanner, monitor, printer, digital camera, copier, proofer, and so on) has to be calibrated with a unique ColorSync profile—a file that tells your Mac exactly how it defines colors. Armed with the knowledge contained in the profiles, the ColorSync software can compensate for the various quirks of the different devices and even the different kinds of paper they print on.
Most of the people who lose sleep over color fidelity are those who do commercial color scanning and printing, where “off” colors are a big deal. After all, a customer might return a product after discovering, for example, that the actual product color doesn’t match the photo on a company’s Web site.
ColorSync profiles for many color printers, scanners, and monitors come built into OS X. When you buy equipment or software from, say, Kodak, Agfa, ...