I set Windows 7 display to high contrast (black background, green foreground) to reduce strain on my eyes, but when I open Toad 13.1 almost all toad selections conforms to the windows setting, except Object Palette. I can see the controls drop down, icons, tabs-actually works, but the data must be black as is the background. The data should be what I set for windows (in my case bright green). Are there settings in toad I can set manually?
I can reproduce this, and after some internal discussion with the other devs, we think we know the cause. unfortunately, i'm not seeing a quick solution for you. I'll at least log this for now, and will let you know when we have a solution.
Update 12/9/2019: Fixed in Toad for Oracle 13.3 Beta