I'm working on the css of a website I'm currently building, and ran in to an interesting conundrum. The jpg image color didn't match up with my gif image. However, the problem wasn't duplicating in other browsers.
Jpg's and Gif images store color information differently, as a result I rarely have jpg images, butting up against gifs that need to match. But in this case converting the swirls to a .gif would triple the file size, and the other image needed transparency, so it had to be a .gif.
When saving your jpg files, in Photoshop, be sure to uncheck "Embed Color Profile".