Two related posts about the same problem. The solved mine 🙂
While working on a new site, I started playing around a little more with 8-bit PNG files, comparing them to GIFs. In a few cases the PNG was smaller (it didn’t used to be that way, but perhaps Photoshop CS2 does a better job of compressing PNG files or something), so used it. All was good until I started testing the design in IE, where the colors were all off. Here’s a breakdown of how the same graphic (placed as a CSS background image against a background color equal to its own background color) rendered between the two browsers:
Easy Reader – PNG color oddities in IE
In setting up the new vehicle details page for DDC, I noticed that the background color for the 24-bit PNGs did not match the css background color, but only in IE6.
Searching online, I found this is a known bug with IE that stems from a flawed interpretation of the PNG’s gAMA setting. It’s fantastic that the IE team added PNG alpha transparency to IE7, but apparently they kept the gAMA bug in IE7 to make sure browser compatibility specialists keep their jobs for years to come.
Netscraps – IE6/IE7 PNG gAMA bug makes PNGs appear darker