How do you find out the file path for an overlay?

[RyreGruel]

Something in my save keeps changing all of my unused overlay slots to "Blank" which is acting the same as it is still treated as being empty by slavetats but still tries to load a texture that doesn't exist. All racemenu tells me is its name is "Blank" and that it also resets the color the transparency each time so I can't hide it that way so the only option left is to actually give it a blank texture to load but I don't know where it is to do that.