Desktop colour settings question - too many choices!

I am finding it difficult to remember which of two almost identical machines I am using when I switch between the two using KVM remote. I need to be able to see at a glance which machine is on screen but do not want any of the behaviours and functions to be changed as this will disrupt how I work.

I am thinking of a change of background colour or some simple flag which is always on screen and indicates which machine I am using.

I spent a short time trying out options using the System Settings>Appearance but these are either are too subtle for me or change the appearance too much.

A change of toolbar colour might be an answer if I could try it but even this has eluded me to date.

Suggestions anybody?

Budge.

Change the cursor theme in use: https://paste.opensuse.org/view/raw/e776c599

Place a second (narrow and otherwise unused) panel at one edge of the screen.

Different wallpapers, assuming you’re not running all applications full screen.

I’m sure there are lots of inventive ways of doing it…

Hi Paul,
Not as simple as you suggest. I tried to select a mouse that would really stand out but didn’t work. Might be a wayland thing, I have no idea what is going on under the bonnet at present.

A vacant space in tray might be a good ploy if I could get one where I want it. So far not successful.

All the other options just not doing it for me. Will keep trying and thanks for the thoughts.
Budge.

Hi
Just have a desktop wallpaper with the hostname on it somewhere…