Color Profiles

When computers first began to achieve the ability to render colorful photo-realistic images on screen, people were more than likely awestruck at the possibilities. Soon after, I can only assume, problems inevitably began to surface.

Anyone who’s ever created an artwork on screen and printed it out has dealt with the disappointment of realizing that the printer doesn’t always consistently print the exact colors you see on screen. Likewise, if you’ve ever used a scanner to scan a photo, what appears on screen is rarely close to the same colors as the original.

We now have a myriad of devices that deal, in some fashion, with digital images. Digital cameras, scanners, monitors (CRTs and LCDs), printers, cellphones (and the list goes on) each have their own unique way of understanding the image and displaying the colors therein.

That’s where Color Management comes in. Enter the world of Color Management and Color Profiles, and you enter a confusing and complex world. I haven’t knowledge or time to explain in depth all that is involved in the intricacies of color management. After all, volumes of books have been written on the subject. This article will fall short of making recommendations on setting up the colors settings in Photoshop or whatever you’re using, but it should help you understand the basics.

The International Color Consortium (ICC) has set up a set of standard “profiles” to be used in order to, in essence, sync up your monitor, scanner, printer, digital camera, etc. This is the main purpose of the ICC Color Profiles. In theory, if everything uses a standard Profile, every device should display similar colors (in theory anyhow). You also, of course, must do a great deal of calibration.

A main point of confusion is often what the Color Profile is. The color profile is a piece of software, associated with a device. The color profile is not in the device itself, somehow intrinsically linked to the hardware, but a piece of software associated with it.

All computer devices understand color as a system of numbers. A Color Profile defines the meaning of the numeric code. For example, it defines what RGB = (234, 12, 23) would mean it terms of color. The numeric values of RGB have no precise meaning, unless they’re associated with a color profile.

Once a color profile has been associated with a document, it is considered Color Managed. And in theory any piece of software that understands color management, such as Photoshop or Illustrator, would be able to understand what the colors are supposed to look like.

Of course, not all documents will be color managed. That’s what “Working Spaces, or Color Spaces” are for. This is where we assign a working color profile for the color model. You are generally better off working with an RGB mode set to an sRGB, because most device assume this profile. To get to the Color Settings in Photoshop (versions 7 and above), click Photoshop, Color Settings (In Windows, it’s located at Edit, Color Settings).

In a very brief nutshell, this is what color profiles are. Color Management is whole other beast.

Color Management

There are three key elements to a Color Management System.

  1. A Reference Color Space. This is the color space that represents the color, as we see it.
  2. Device Color Profiles. This is the color profile that will describe the color for a specific device. (It describes what RGB = (234, 12, 23) means to your digital camera, or to your monitor, or to your printer, etc)
  3. A Color Engine. This is also called the Color Matching Method (CMM). It is a piece of software that translates the profiles. In other words, it matches the red in the monitor with the red in the scanner, by looking at each of the Device Color Profiles and translating the numeric data.

These three elements keep the Color Management System working. What happens (in grossly over-simplified terms) is this:

  1. You scan a sheet of yellow paper. The scanner sees this yellow as RGB = 246,231,68.
  2. The Color Engine looks at the Device Color Profiles for the monitor and for the scanner and translates the numbers. It then knows that the yellow paper you scanned would not best be represented by RGB values of the scanner, but by RGB = 243, 229, 72. So your monitor displays these adjusted numbers.

What the Color Engine does not do, is change the numbers in the file. It merely adjusts the way your monitor displays them, so that the yellow appears on your screen similarly to the actual yellow you scanned.

Now, to make things a bit more complicated, Photoshop does not encourage the use of Color Space that is based on any specific device. Photoshop (and also Illustrator) uses abstract RGB spaces. It completely by-passes monitor color profiles and does a bit of translating itself, sending the translated data to the video card, so that the color will be correct on whatever monitor is being used. But the basic principle is the same.

Setting up the system

Obviously, developing a Color Management System can get hairy, what with the myriad of devices and different color profiles needed to deal with each one. The purpose of this article is to give a general overview of what Color Management is, not to make specific recommendations of how to develop your own and it has probably raised more questions than answers.

To get a better understanding of the specifics of what you need to do, and where I got most of the information for this article, try the following: