The problem is that we have several different components in Toad, each with their own color schemas.
There is the VCL, which comes with Delphi (our programming environment for Toad), and includes standard buttons, panels, etc.
There is the menus , toolbars, and grids, which are Developer Express components
There is the syntax editor, which is Scintilla,
VirtualStringTrees (which maybe can follow VCL)
And probably something else that I'm forgetting and the moment.
It probably wouldn't be very difficult to enable on a "dark mode" for each of these components (which we've done, internally while researching this possibility). The problem is that none of them match and it's quite a mish-mash.
It is on our radar though.