What theme is main and what theme was applied specifically to WB10config.exe?
But do know that, what ever theme applied to main will have full control on system colors. Which is, if the main theme change the Windows font color (System Colors) to white, that color will be same for all other theme applied to other apps.
For reference. Below is my screen shot where my main theme is Simplic Classic and my WB10Config.exe is set to use "Eva". Since my Simplic Classic is using Black on Windows Text.

But if I use My Simplic Classic Dark, which change Windows System Font color to light gray. That color will be carry over to all apps. Even for those apps you exclude from Windowblinds.

Thank you,
Basj,
Stardock Community Assistant