Orange screen after uninstall
I looked up this topic on an earlier post and tried following your directions. There is no f.lux entry in applications or displays or the activity monitor. @fidget we can help. Do you have a f.lux profile in your System Preferences > Displays section? You can delete it. And also to verify that you aren't running f.lux anywhere search for "flux" in Activity Monitor and force quit it.
I also tried the command from this page https://www.cnet.com/news/how-to-make-colorsync-profiles-stick-in-os-x/ , but it said there was no such folder. The orange goes away when I open system preferences > displays, but then comes back.