Icon in the status bar.

In the status bar is always the same icon. It would be great if the icon changed depending on IMPACT, SCAN, SYNCHRONIZATION.

There’s no such thing as status bar icon in Syncthing. Some wrappers (syncthing-gtk, syncthing-macos and synctrayzor, to name a few) add a status bar icon as part of their UI. If the issue you are describing bothers you, the best way would be to find out how to contact the maintainers of the wrapper you use, and figure out how to help them fix it.

Now, if you’re talking about syncthing-android, that one is a wrapper, too, and this indeed is the forum to contact people developing it. But you’d better say explicitly that it’s Android you’re concerned about.

I think there is also some magic javascript to juggle the favicon in the web UI. It’s not supported by all browsers.

Yes, I’m sorry, I mean syncthing-android.