All images below have the same RGB values, but the sRGB and Gamma information in the PNGs is different. Depending on your browser and operating-system color profile, all images may look the same or different.
|CSS||GIF||PNG bare||PNG sRGB|
|PNG g=2.2||PNG g=1.8|
Of the mainstream browsers, only Apple Safari is supposed to use embedded color profiles, which means that it transforms the RGB values before sending them to the operating system (Mac OS X). The operating system then applies the system color profile (generic sRGB or a monitor-specific profile) before sending the data to the monitor.
The other mainstream browsers (Firefox 1.5/2.0, Opera 8/9, Internet Explorer 6/7) presumably pass the raw RGB values from the images without any transformation to the operating system, which would mean that all images look identical.
Explanation of the image captions:
See also: The Sad Story of PNG Gamma "Correction" .