Today, to great fanfare (and an embarrassing server crash) Firefox 3.0 got released. This is a great and fast browser even if on the Mac I prefer Safari. One of the promises it held was that finally, there would be a mainstream browser outside Safari that supports color management. Unfortunately, it is not enabled by default which is a very bad decision. There is no good reason for this and the quoted reasons (incorrect color in pages that mix CSS elements and images) is just plain wrong technically. Color managed apps will only color manage images that have a profile. Image elements on webpages never have those, so the appearance will not change. Luckily, there is an option to enable color management in Firefox that is hidden in the secret configuration pages. You enable it by typing "about:config" in the address bar (without quotes). Click "I'll be careful" and you'll get a page with many obscure settings. In the Filter box, type "management" and the only two relevant options will come up. Make sure that display_profile is set to the default, and double click on the"enabled" property to change its value into "true." This will turn on color management and will make those images on the web that have profiles embedded appear as they were meant (as long as you have calibrated your monitor). Even images in sRGB will benefit from this. This really should be the default and I think it is a major error that they did not enable this at least as a visible preference. Next time better I hope.
To learn why this is really important, see this excellent explanation. Test your color managed browser here.
Edit: it turns out that Firefox 3.0 color manages every image, even untagged ones. That is a superb choice!