I don't think this is a color issue, as the whole thing is in black and white to begin with.
I have five layers, all dark black against (what would you call the main background that isn't assigned a layer?) a background that is now faded to grey. You can't adjust the opacity on this "base layer", and I've moved it everywhere from the top "step" to the bottom, and it's not changing. Any thoughts on what I might have done?
This might be helpful, at one point I made a huge white square over most of the image (not all) with opacity at about half so that on just one layer I could make everything seem darker. I can't seem to find that square anymore, even with all layers off, but the whole thing has turned grey, not just what was inside the square.
I know this is convoluted, any help appreciated!