The Alba Tank sensor and light is a great addition to the Gaggimate system, on my Gaggia E24. It was easy to install, except that the sensor mounted connector pulled loose when installing. Make sure it is fully seated! I ended up using the double sided tape to attach the sensor to the machine. The magnet and screw system was fiddly and wasn't very secure.
Once installed, the light works well, glowing blue when in standby, then changing to green when the brew is complete. It glows red if there's an error or the tank level goes too low. I can't discern if there's a different colour while the machine is brewing, maybe a slightly different blue?
Also, I thought the settings would allow for changes to the colour settings or intensity but that doesn't seem to work. Maybe I'm missing something.
Kudos to the Gaggimate team for continuing to improve the system.
Gaggimate has transformed my humble Gaggia Classic into a powerhouse espresso machine.