You could do the opposite and light the area around the button and not need translucent buttons it would be an outline of the buttons. I think some equipment manufacturers have done this as a retrofit instead of a button change and it would only take one per left hand button and one for volume knob. The lighted buttons would look cooler.
I really like the fiber optic solution.

#695 Mk2 BLUE 12Gig

Ask and I may tell you