sometimes I find the dimmed sections , a bit difficult to read - I think perhaps depends on ambient light as sometimes it’s fine?!
Hard to think of an alternative…
I think it’s has to be really obvious which section is active at a glance , as it would be very frustrating turning encoders to suddenly realize you’d change the wrong parameter as you were in the wrong section. … so I don’t think it should be subtle at all.
in this regard current solution is really good,
I think personally your solution is too subtle for my tastes.
(actually, I didnt even notice your indicators when I first read your post!)
If I was to go the route of using indicators, Id put them on the other side,
for a UX/UI standpoint - they should be on the same side as the selection button, so the user associates the hardware buttons and the indicators. perhaps 3 side bars, on the left which are grey , and the active section is white.
but honestly, I still think thats too subtle…
essentially the user would be subconciously having to look for the indicators, before they ever touched an encoder , to ‘check’ which section was active.
thats why I think doing something with control (like dimming as done currently) is better.
Perhaps we could post some mock ups ( images) we think might work - see if @martin and others like them ?!