Ah... well... there's an interesting story there.
I don't know what the current situation is with Calrec, but I believe Studer tried to prevent Calrec from using their coloured ID strips alongside the faders by claiming the patent they somehow were granted on their own 'FaderGlow' system covered Calrec's system too because it was conceptually similar (but physically completely different).
Studer's engineering of the FaderGlow system is quite clever and typically Swiss. But I still struggle to understand how they could claim FaderGlow as a unique invention when the concept of electronically selectable coloured, back-lit faders or fader slots or fader escutcheons, as an aid function identification, pre-dates their design by nearly fifty years, and with at least four practical implementations of similar schemes in existence in the UK alone!
The first implementation of the idea that I know of was with the Painton faders, as already discussed. The next I know of was when SADiE introduced coloured virtual fader slots to indicate different fader automation modes in V3.0 of their DAW, which was around 1996. One of the nicest implementations of the concept of changing fader colour to indicate function was from Audix Broadcast (UK). They showed a really clever and fully functional prototype system in 2001 where the actual fader knob changed colour. Sadly, AFAIK no commercial product was ever made with their technology. Calrec's system on the Apollo desk (as in the image above) was around the early 2000s, as in your picture and it used a strip of multicoloured LEDs running alongside the fader slot.
In contrast Studer's FaderGlow system uses an end-lit perspex strip mounted inside the fader slot.