What do the lights on a Sterling alternator controller mean?

On Jubilee there is a Sterling "advanced digital four step split charge alternator to battery charger". Even though I've read the instruction leaflet I'm still not sure exactly what it does. Jubilee has two alternators, each of which connects to the Sterling device. There are outputs to both the starter battery and the domestic battery bank. Visible through a window are several LED indicator lights, but there is a large amount of parallax error when trying to line up the LEDs with the legends on the case, as I've illustrated with the photos.




In both photos the same LEDs were on. To make it more complicated, some of the LEDs appear to be multicoloured. What do the colours mean?