Between Tor Browser 13.0 and 13.5, we simplified the onion pattern present at the foot of about:tor and about:torconnect. In the case of the latter screen, an asset was supplied for light theme, but not dark theme. Looping in @henry for implementation (when ready). See https://gitlab.torproject.org/tpo/applications/tor-browser/-/merge_requests/1025#note_3029510 for details.