Taskbar images are darkened when I modify them

[ChrisERAU]

Everytime I change/replace an image to use as the taskbar buttons, the image gets darkened. I'm not sure if others have had this issue, but if makes trying to change taskbar icons extremely frustrating. For example, I'd change just a part of the image, save it, then test it. Of course, the entire image gets darker somewhere along the way, so I open up the original image and the modified image, just to make sure.