Grey Border Around Transparent GUI
From The DarkMod Wiki
posted by Springheel
This problem keeps cropping up, so I'm storing solutions here as I find them.
For some reason, a .tga image with a transparent background will sometimes apply a thin grey border around the object in the center. This doesn't happen all the time, but it's annoying when it does. I haven't been able to track down the cause.
I've had no trouble adding graphics with transparencies before while working on the failure and success screens, so I can't figure out what's going on. Even a simple black box gives me a grey border.
It might have something to do with soft edges around the object, although sometimes it seems to happen with solid edges as well. I'm working on this issue right now so I'll post some more shortly.