Why not? Why did nobody do it before? Not backlighting the slots is patented but functional signaling for audio mixers is the property. It's fed by a RGB-LED. E.g. it shows you the function of a fader (InputChannel, Busses, Masters, etc.) or if you use it as monitor mixer on stage and you go into GraphicEQ-mode to tune the monitoring, the faders all turn yellow and act as the actual EQ band-levels. ... you see... you have to try harder ;) Greets, Roger