I think you might be slightly misunderstanding the implementation.
The knob displays a colour but does not display an encoder position. There is an example that got built as an experiment . Zynthian MIDI-UB Controller
It also demonstrates the difficulty of lining up lights and encoder pointers !!
But what I’m working with are encoders that have one settable colour. Now there are few things we can do.
1/ Set the colour of four knobs to match the GUI display colour.
This would give a strong conformity of look.
2/ Set the colours in the GUI to match colours individually displayed by the knobs. Very strong linking that would make the Interface more intuitive. ( Might also end up looking ghastly… I like the simple colour look, althou the green in play/record looks good against the red IMHO)
The big advantage of what we do have is the closing of the loop for sending a message into the zynthian world and receiving some form of acknowledgement back down a status channel.
Possibly this would simply be used to reflect different states. i for one would see the MIXER layer being a different colour to the other layers simply to make it instantly recognisable when glanced at. Perhaps the overall volume might be specifically identified when it’s active.
Much to think about. In a multi zynth environment it becomes good way of differentiating the different devices and would make for a fairly intuitive remote mixer interface.
The box that jofe built would obviously would be supported in a similar fashion if we had a 12C positional encoder LED thingy. …