I can confirm David Carment's non-smoking observation:

On my 82 Westy, the refrigerator LED is red.  It looks like it's tied
right to a thermocouple watching over the flame, as the intensity of the
LED varies with the vigor of the flame.  This LED signals NOTHING at all
when the fridge is running in 12V or 120V mode.

Just to breathe some propane into the debate, I swear I have seen some
later-than-82 Westy control panels with a single BLUE LED, which I assumed
was the refrigerator LED, as there were still the two "stoplight" LED trios
showing battery condition and water level.

The only Dometics with gauges instead of LED's that I have seen were in
pre-Vanagons.