I uninstalled WindowBlinds after two weeks of the trial period. I used Revo Uninstaller to do this, although it first ran the WB uninstaller before removing remaining traces of WB. After rebooting I discovered that elements of the WB skin were still in place! I then downloaded and ran (as Administrator) the Purge_WB.bat (available from https://cdn.stardock.us/support/uploads/Purge_WB.zip), and again after rebooting - the the WB skin (dark mode) still exists. It is especially noticeable for Office 365 Excel - the spreadsheet remains dark gray.
How can I completely remove WB from the system? Windows 10, latest version as of Feb 5 2019, Lenovo Ideapad 720s.