Turn off LEDs on adalight if Hyperion is offline

I needed to power my Android corelec box from my TV's USB, as I didn't find another way to turn on/off as requested.

As this work now flawlessly it leaves adalight on the Arduino Nano running in a unknow state. The Android's power is just cut, Hyperion.NG dies instantly and the LEDs keep showing the LEDs they showed at last.

Do you know of and way to tell adalight to just turn OFF all LEDs in case there is no serial input (anymore)?

Thanks