Color Management

Color Profiles in Photoshop:
For PRINT: use ADOBE RGB 1998
For WEB: use sRGB

When you color-manage documents that will be viewed exclusively on the web, Adobe recommends that you use the sRGB color space. sRGB is recommended for web because it defines the color space of the standard monitor used to view images on the web.
To change color profiles in Photoshop, go to EDIT > Assign Profile. Your monitor/workspace in Photoshop should always be set up in ADOBE RGB. To make sure it is, go to EDIT > COLOR SETTINGS. Choose "North American Prepress 2" and under working spaces, the top RGB slot should say Adobe RGB 1998. Leave everything else as is.

Preparing your Files for Web
When working with images that have an embedded color profile other than sRGB, you should convert the image’s colors to sRGB before you save the image for use on the web.
In Photoshop CS3, there is a function that helps you save your images for web properly, so that you don't have to convert all the profiles manually. Go to FILE > SAVE FOR WEB & DEVICES. It automatically saves it as sRGB, and you can resize the file as well. Remember, appropriate web size is usually in the range of 500x500 pixels. Under the Quality tab, choose Bicubic Sharper as it generally produces better results when you are reducing image size.


I saved this same file in Photoshop 2 different ways. Notice that the one I saved as sRGB looks a little better...the colors are more vibrant. The one I saved as Adobe RGB looks a little desaturated, because this is the incorrect color profile. Adobe RGB is for making prints only.

* the difference is subtle, but notice the redness of the raspberry in each.

sRGB


Adobe RGB 1998


In the dialog box at the left inside the "Save for Web" window, there are various boxes you can check. I recommend checking "Progressive" (which automatically optimizes your image) and leaving ICC unchecked. Here's what they all mean:

QUALITY Determines the level of compression. The higher the Quality setting, the more detail the compression algorithm preserves. However, using a high Quality setting results in a larger file size than using a low Quality setting. View the optimized image at several quality settings to determine the best balance of quality and file size.
OPTIMIZED Creates an enhanced JPEG with a slightly smaller file size. The Optimized JPEG format is recommended for maximum file compression; however, some older browsers do not support this feature.
PROGRESSIVE Displays the image progressively in a web browser. The image appears as a series of overlays, enabling viewers to see a low-resolution version of the image before it downloads completely. The Progressive option requires use of the Optimized JPEG format.
ICC PROFILE Preserves the ICC profile of the artwork with the file. Some browsers use ICC profiles for color correction. This option is available only after you saved an image with an ICC profile—it is not available for unsaved images.