Normally I use Firefox as my favourite browser, but in the latest version 3.5 (or precise: 3.5.1) color correction is turned on by default. In some cases this is nice i.e. when viewing photographs, BUT in webdesign this is a disaster! I.e. many PNG’s are not rendered "correctly" or in the way they are suppose to. Often they appear darker than expected by the designer. Say you have a PNG image with a color which is meant to be the same as the body’s background color but when it is rendered the colors don’t look identical.
I have googled the problem and found several other forums which discuss this issue, but I thought it would be interesting to get the opinion from some CSS-tricks-guys.