Hello,
Sorry to hear you are having issues. Need to clarify something, when you said you uninstalled ObjectDesktop, did you also uninstalled all Stardock applications that you installed before? Such as Windowblinds, Start11, Groupy, Fences etc? If you did uninstalled them individually, did you do a reboot after each uninstalled? Also. To get back to default, Windows theme you might need to manually apply Windows theme. Refer screenshot below. This should get back your system back to default Windows theme. You can than set back your color mode to dark or light.
Windows 11.
Thank you.
Basj,
Stardock Community Assistant.