Color management is a way of trying to keep colors consistent across a range of input, display and output devices by the use of software and profiles that describe the color characteristics of particular devices.

Photoshop should be set to sRGB as the working color space, or Adobe RGB if you really know what you are doing.

The color space profile for an image may be imbedded into the image file or the file's color space labeled by a color space tag in the metadata.

Image files may lose their color space tags when calibrated in some astronomical image processing programs. If you know that your camera is set to a particular color space and the image opens in Photoshop and you get a dialog box that says the profile is missing, then you should assign the correct color space.

When you output to a particular device, you should convert from the image's working color space to the color space of the output device.

Images destined for display on the web, or on another computer monitor, should be converted to sRGB if they are not already in sRGB color space.

Desktop printers come with profiles from the manufacturer. Convert your image to the particular profile for your printer and the inks and paper you are going to print on. In later versions of Photoshop, this is done by: Edit > Convert to Profile. In earlier versions of Photoshop this is done by: Image > Mode > Convert to Profile.

Always remember to make a copy and convert the copy so that the original enhanced image is preserved.

After the color space conversion for printing, the chances are good that the colors and tones of the image will not look exactly the same as your original image. This is because of the fundamental difference between your monitor and a print. A monitor is an emissive light source that creates color by adding three primary colors together, red, green and blue. A print creates color by a subtractive reflective method of absorbing colors from white light with cyan, magenta and yellow pigments. These two methods have limitations on the colors they can reproduce. Some colors can be seen on a monitor that just can not be reproduced in a print, and vice versa.

After the conversion, it is possible, to a degree, to adjust the color image in Photoshop to make it somewhat closer to the way you envision it. However, you must accept the fact that it will never match exactly.

Photoshop vs Web Browser Display

If you have your monitor set up correctly, and have created a monitor profile with a hardware calibration device, the display of an image in Photoshop in any color space should be very close to the display of the same image in a web browser window after the image is converted to sRGB for web use.

Frequently it turns out that TIFF images displayed in Photoshop look different than the exact same image saved as a JPEG and displayed in a web browser. This is usually because of one or more of the following reasons:

• The color space settings are not set up correctly in Photoshop
• The image has not been converted to sRGB correctly
• The monitor has not been profiled correctly
• There is something wrong with the monitor
• You did not correctly embed the color space profile
• Your web browser does not support color space profiles

Most web browsers do not correctly support color space profiles. Gearoracle has a good web browser color management guide that explains which browsers do, and also a test page so you can see what your browser is doing. I use Firefox 3.6 because it comes the closest to working correctly with color space tags.

The following procedure can be utilized to test to see if you have your system set up correctly:

1. Calibrate your monitor and create a monitor profile.

2. Open Photoshop set the working color space to Adobe RGB (1998) in Edit > Color Settings. Make sure the Preview box is checked ON in the Color Settings setup dialog box.

3. Open a test image in Photoshop. The file should be in some color space. If it is not, assign the working Adobe RGB (1998) color space to the file:

   • CS2: Edit > Assign Profile
   • Previous versions of Photoshop: Image > Mode > Assign Profile > Adobe RGB (1998)

   The working color space for the file can be displayed in the Status Bar at the bottom of the Photoshop window. If it is not visible, go to Window > Status Bar in the pull down menus at the top. Click on the right pointing triangle in the Status Bar and select "Document Profile". The image's color space will now be displayed to the left of the triangle in the status bar.

4. Save the image as a TIFF file and name it something like Test-Adobe RGB.tif. Make sure the ICC Profile box is checked ON in the Save As dialog box and that is says Adobe RGB (1998). This will embed the Adobe RGB (1998) color space profile into the file.

5. Convert the image to the sRGB color space for output to the web or email.

   • In CS2 and higher: Edit > Convert to Profile: Destination Space - sRGB ICE61966-2.1
   • In previous versions of Photoshop: Image > Mode > Convert to Profile > Destination space: sRGB ICE61966-2.1.
   • Leave everything else set to the defaults.

6. Save the converted image as a JPEG with the name Test-sRGB.jpg.

   CHECK the box next to the ICC profile in the Save As dialog. This will save the file with the color space profile embedded in it.

7. Open Test-sRGB.jpg in Internet Explorer or Netscape or Opera. You may have to embed the image file in a simple html page.

8. Tile Photoshop and Internet Explorer by right clicking on a blank area of the task bar in Windows and choosing "Tile Windows Vertically".

9. In Photoshop, go to View > Proof Setup > Monitor RGB.

10. Compare the image Test-adobe.tif in Photoshop to the image Test-sRGB.jpg in the browser. They should look identical.

    If they don't, you have something set up wrong, or your monitor is going bad.