on macOS 27 Golden Gate running Orion Version 1.1.3 (152), WebKit 625.1.8 in Vertical Tab mode with "Allow Website Theme color" toggled off, some active tabs cause the sidebar to go to a sick-white instead of the UI's Dark mode like the top toolbar. If I switch to another tab of a site, the sidebar goes back to it's appropriate color.
Broken

The sidebar in Vertical Tab mode should stay the same dark as the toolbar, not switching background color based on active tab.
Normal Sidebar

macOS 27.0, Orion Version 1.1.3 (152), WebKit 625.1.8
Tahoe (26)