Problems with colors in IE

[Walalayo]

I've been having a problem where IE doesn't display the correct colors.

The situation: I have one image that's pink. I have another image that is the same color pink, according to Photoshop (same RGB hex code). The images are in individual HTML layers. The second image is in a javascript navbar. The navbar is superimposed over the simple pink graphic.

The problem: IE displays the navbar images as slightly darker than the background pink, which means you can see the edges of the navbar. Firefox doesn't have this problem. It's not just my comp, I've tried it on other machines with the same result.

Any ideas on what might be causing this/what I can do to fix it?

Thanks